DOC C. TOPICS ONLY AI HIGH YIELD

A researcher identifies a DNA variant in an intronic region that does not directly alter protein structure but consistently segregates with a hereditary renal disorder in a family. What is the best use of this variant?

• A. Direct causative mutation

• B. Linkage marker

• C. Oncogenic driver

• D. Epigenetic silencer

B. Linkage marker

A patient has different numbers of large contiguous DNA segments compared with a reference genome. Which type of genetic variation best explains this?

• A. Single nucleotide polymorphism

• B. Copy number variation

• C. Missense mutation

• D. Histone acetylation

B. Copy number variation

A tumor suppressor gene is transcriptionally silenced even though sequencing shows no mutation in the coding region. The promoter region is densely methylated. What process is responsible?

• A. Genetic deletion

• B. Epigenetic modification

• C. Copy number gain

• D. Chromosomal translocation

B. Epigenetic modification

A female cell transcriptionally silences one X chromosome through coating by a long noncoding RNA. Which molecule mediates this process?

• A. miRNA

• B. XIST

• C. Dicer

• D. RISC

B. XIST

A small RNA binds to complementary mRNA and reduces protein production without encoding a protein itself. Which molecule is being described?

• A. miRNA

• B. tRNA

• C. mRNA

• D. rRNA

A. miRNA

A drug inhibits histone deacetylases. What is the most likely effect on chromatin?

• A. Condensation with decreased transcription

• B. Opening with increased transcription

• C. DNA strand break formation

• D. Telomere shortening

B. Opening with increased transcription

A therapeutic gene-editing system uses guide RNA to target DNA and creates a double-stranded break repaired by non-homologous end joining or homologous recombination. Which system is being used?

• A. RNA interference

• B. CRISPR-Cas9

• C. DNA methyltransferase inhibition

• D. Proteasomal degradation

B. CRISPR-Cas9

A plasma membrane protein crosses the lipid bilayer several times through hydrophobic alpha-helices. Which classification is most accurate?

• A. Peripheral membrane protein

• B. Integral transmembrane protein

• C. GPI-anchored protein

• D. Extracellular matrix protein

B. Integral transmembrane protein

A membrane lipid normally located on the inner leaflet becomes exposed externally and marks a cell for phagocytosis during apoptosis. Which lipid is this?

• A. Phosphatidylinositol

• B. Phosphatidylserine

• C. Sphingomyelin

• D. Cholesterol

B. Phosphatidylserine

A red blood cell surface antigen depends on oligosaccharide chains extending from the external surface of the plasma membrane. Which structure is most involved?

• A. Glycocalyx

• B. Lipid raft

• C. Caveola

• D. Tight junction

A. Glycocalyx

A polar epithelial cell maintains distinct apical and basolateral domains by sealing paracellular spaces. Which junction performs this function?

• A. Desmosome

• B. Hemidesmosome

• C. Tight junction

• D. Gap junction

C. Tight junction

A breast carcinoma shows discohesive invasion due to loss of E-cadherin. Which junction is primarily affected?

• A. Adherens junction

• B. Gap junction

• C. Tight junction

• D. Hemidesmosome

A. Adherens junction

A skin biopsy from stratum spinosum shows strong mechanical adhesion between epithelial cells through intermediate filaments. Which structure is responsible?

• A. Hemidesmosome

• B. Desmosome

• C. Gap junction

• D. Tight junction

B. Desmosome

A blistering disorder disrupts epithelial attachment to basement membrane by impairing integrin-based adhesion. Which junction is affected?

• A. Hemidesmosome

• B. Desmosome

• C. Adherens junction

• D. Connexon

A. Hemidesmosome

Cardiac myocytes require rapid movement of ions and small molecules between adjacent cells. Which junction allows this direct communication?

• A. Tight junction

• B. Gap junction

• C. Desmosome

• D. Focal adhesion

B. Gap junction

A secretory cell producing large amounts of protein has abundant ribosome-studded membranes. Which organelle is most prominent?

• A. Smooth ER

• B. Rough ER

• C. Peroxisome

• D. Lysosome

B. Rough ER

A hepatocyte exposed to phenobarbital shows proliferation of an organelle involved in detoxification by cytochrome P450. Which organelle expands?

• A. Rough ER

• B. Smooth ER

• C. Golgi apparatus

• D. Lysosome

B. Smooth ER

A premature newborn develops jaundice due to impaired bilirubin conjugation. Which organelle performs the conjugating function?

• A. Smooth ER

• B. Lysosome

• C. Peroxisome

• D. Nucleolus

A. Smooth ER

A lysosomal enzyme is synthesized but fails to reach lysosomes because its sorting tag is absent. Which tag is most likely defective?

• A. Ubiquitin

• B. Mannose-6-phosphate

• C. Phosphatidylserine

• D. Acetyl-CoA

B. Mannose-6-phosphate

A damaged mitochondrion is enclosed in a double membrane and degraded after fusion with lysosomes. What process is this?

• A. Pinocytosis

• B. Mitophagy

• C. Exocytosis

• D. Transcytosis

B. Mitophagy

A cytosolic protein is tagged with ubiquitin for degradation. Which structure performs the degradation?

• A. Lysosome

• B. Proteasome

• C. Golgi apparatus

• D. Smooth ER

B. Proteasome

A cystic fibrosis patient has misfolded ΔF508 CFTR retained and degraded before reaching the membrane. Which cellular response is most directly involved?

• A. ER quality control

• B. Lysosomal exocytosis

• C. Nuclear translocation

• D. Peroxisomal oxidation

A. ER quality control

A patient with prolonged ER stress accumulates misfolded proteins. If adaptive responses fail, what is the most likely cellular outcome?

• A. Apoptosis

• B. Metaplasia

• C. Hyperplasia

• D. Hypertrophy

A. Apoptosis

A renal tubular cell transports glucose from the tubular lumen with sodium using the sodium gradient. Which transport type is this?

• A. Primary active transport

• B. Secondary active transport

• C. Simple diffusion

• D. Clathrin-mediated endocytosis

B. Secondary active transport

A steroid hormone crosses the plasma membrane without a transporter and binds an intracellular receptor. Why can it cross easily?

• A. It is lipid soluble

• B. It is highly charged

• C. It is bound to mannose-6-phosphate

• D. It requires clathrin-coated pits

A. It is lipid soluble

A large polar molecule cannot passively diffuse across the plasma membrane. Which property most limits its diffusion?

• A. Large size and polarity

• B. Lack of ATP

• C. Absence of DNA methylation

• D. Lack of histones

A. Large size and polarity

A cell takes up LDL through coated pits and vesicles requiring dynamin. Which process is this?

• A. Caveolae-mediated endocytosis

• B. Clathrin-mediated endocytosis

• C. Phagocytosis

• D. Transcytosis

B. Clathrin-mediated endocytosis

A small molecule enters the cell through cholesterol-rich, caveolin-containing membrane invaginations. Which process is involved?

• A. Caveolae-mediated endocytosis

• B. Clathrin-mediated endocytosis

• C. Phagocytosis

• D. Autophagy

A. Caveolae-mediated endocytosis

A macrophage engulfs bacteria into a phagosome that later fuses with lysosomes. Which pathway delivers the substrate to lysosomes?

• A. Phagocytosis

• B. Exocytosis

• C. Proteasomal degradation

• D. Passive diffusion

A. Phagocytosis

A sperm cell's flagellum is immotile due to defective axonemal structure. Which cytoskeletal component is most involved?

• A. Intermediate filament

• B. Microtubule

• C. Actin microfilament

• D. Lamin

B. Microtubule

A tumor's tissue origin is suspected to be epithelial. Which intermediate filament is most useful to support this?

• A. Vimentin

• B. Desmin

• C. Cytokeratin

• D. Neurofilament

C. Cytokeratin

A sarcoma stains strongly for vimentin. Which tissue lineage is most suggested?

• A. Epithelial

• B. Mesenchymal

• C. Neural

• D. Glial

B. Mesenchymal

A muscle tumor stains positive for desmin. Which lineage is most supported?

• A. Muscle

• B. Glial

• C. Epithelial

• D. Endothelial only

A. Muscle

A glioma stains positive for GFAP. Which intermediate filament supports the diagnosis?

• A. Cytokeratin

• B. Vimentin

• C. Glial fibrillary acidic protein

• D. Desmin

C. Glial fibrillary acidic protein

A rapidly dividing cell preferentially uses aerobic glycolysis despite adequate oxygen to generate biosynthetic intermediates. Which mitochondrial-related metabolic phenomenon is this?

• A. Pasteur effect

• B. Warburg effect

• C. Oxidative phosphorylation

• D. Nonshivering thermogenesis

B. Warburg effect

Brown adipose tissue produces heat by dissipating the mitochondrial proton gradient. Which protein is responsible?

• A. Caspase-9

• B. UCP-1

• C. Cytochrome c

• D. ATP synthase

B. UCP-1

Intrinsic apoptosis begins after DNA damage and mitochondrial outer membrane permeabilization. Which molecule released from mitochondria initiates apoptosome formation?

• A. BCL-2

• B. Cytochrome c

• C. FAS ligand

• D. TNF receptor

B. Cytochrome c

A growth factor binds EGFR and induces receptor dimerization and autophosphorylation. Which receptor class is this?

• A. G-protein-coupled receptor

• B. Receptor tyrosine kinase

• C. Nuclear receptor

• D. Ligand-gated ion channel

B. Receptor tyrosine kinase

Nitric oxide diffuses into smooth muscle and causes vasodilation through which second messenger?

• A. cAMP

• B. cGMP

• C. IP3

• D. DAG

B. cGMP

A steroid hormone binds a cytosolic receptor that enters the nucleus and directly regulates gene transcription. Which receptor type is involved?

• A. Nuclear receptor

• B. Ion-channel receptor

• C. Connexon receptor

• D. Clathrin receptor

A. Nuclear receptor

A pathway stabilizes β-catenin, allowing nuclear entry and transcriptional activation. Which signaling pathway is this?

• A. Notch

• B. Wnt

• C. JAK-STAT

• D. TGF-β only

B. Wnt

A ligand binds a receptor that undergoes proteolytic cleavage; the released intracellular fragment enters the nucleus. Which pathway is this?

• A. Notch signaling

• B. GPCR signaling

• C. Caveolin signaling

• D. Clathrin signaling

A. Notch signaling

A growth factor is strongly angiogenic after injury and in tumors, induced by hypoxia through HIF-1. Which growth factor is this?

• A. PDGF

• B. VEGF-A

• C. TGF-β

• D. HGF

B. VEGF-A

A renal carcinoma overexpresses MET receptor signaling. Which growth factor receptor pathway is most implicated?

• A. HGF/scatter factor

• B. VEGF

• C. PDGF

• D. EGF

A. HGF/scatter factor

A chronic inflammatory lesion becomes fibrotic because a cytokine increases collagen and fibronectin synthesis while inhibiting matrix degradation. Which cytokine is most responsible?

• A. IL-8

• B. TGF-β

• C. TNF

• D. IFN-γ

B. TGF-β

Vitamin C deficiency causes poor wound healing because of impaired cross-linking of which ECM protein?

• A. Elastin

• B. Collagen

• C. Laminin

• D. Fibronectin

B. Collagen

A patient with Marfan syndrome has weak aortic walls due to defective elastic fiber scaffold. Which protein is defective?

• A. Fibrillin

• B. Type IV collagen

• C. Laminin

• D. Nephrin

A. Fibrillin

A basement membrane is primarily composed of laminin and which collagen type?

• A. Type I

• B. Type II

• C. Type III

• D. Type IV

D. Type IV

A cell cannot pass the G1/S checkpoint after DNA damage because p53 is activated. What is the primary purpose of this checkpoint?

• A. Confirm spindle attachment

• B. Verify DNA integrity before replication

• C. Separate chromatids

• D. Complete cytokinesis

B. Verify DNA integrity before replication

Cyclin E activity is most important for which cell-cycle transition?

• A. G1 to S

• B. S to G2

• C. G2 to M

• D. M to G0

A. G1 to S

A patient with right-sided heart failure develops lower extremity edema. Which hemodynamic mechanism is most responsible?

• A. Increased hydrostatic pressure

• B. Increased plasma oncotic pressure

• C. Decreased vascular permeability

• D. Increased lymphatic drainage

A. Increased hydrostatic pressure

A patient with nephrotic syndrome develops generalized edema. Which mechanism is dominant?

• A. Increased plasma oncotic pressure

• B. Decreased plasma oncotic pressure

• C. Decreased sodium retention

• D. Arterial vasoconstriction only

B. Decreased plasma oncotic pressure

A woman develops arm swelling after mastectomy with axillary node dissection. Which edema mechanism is present?

• A. Lymphatic obstruction

• B. Increased oncotic pressure

• C. Decreased hydrostatic pressure

• D. Increased platelet adhesion

A. Lymphatic obstruction

Chronic passive congestion of the lung produces brown induration. What cell/pigment combination explains the brown color?

• A. Neutrophils with melanin

• B. Macrophages with hemosiderin

• C. Fibroblasts with lipofuscin

• D. Type II pneumocytes with bilirubin

B. Macrophages with hemosiderin

Chronic passive congestion of the liver produces nutmeg appearance. Which zone is most vulnerable to hypoxic injury?

• A. Periportal zone 1

• B. Midzonal zone 2

• C. Centrilobular zone 3

• D. Bile duct epithelium only

C. Centrilobular zone 3

Platelets adhere to exposed subendothelial collagen through a bridge molecule. Which molecule is essential?

• A. Albumin

• B. von Willebrand factor

• C. Thrombomodulin

• D. Protein C

B. von Willebrand factor

Aspirin decreases arterial thrombosis by inhibiting synthesis of which platelet mediator?

• A. Thromboxane A2

• B. Prostacyclin

• C. Fibrinogen

• D. Plasmin

A. Thromboxane A2

Endothelial thrombomodulin binds thrombin and converts it into an anticoagulant enzyme. Which protein is activated?

• A. Protein C

• B. Factor X

• C. Fibrinogen

• D. Plasminogen

A. Protein C

A patient has repeated DVTs and pulmonary emboli with normal PT, PTT, and platelet count. Which inherited cause is most likely?

• A. Factor V Leiden mutation

• B. Vitamin K deficiency

• C. Hemophilia A

• D. Thrombocytopenia

A. Factor V Leiden mutation

A young woman has recurrent thrombosis, miscarriage, false-positive syphilis test, and prolonged PTT. What is the most likely cause?

• A. Antiphospholipid antibody syndrome

• B. von Willebrand disease

• C. Factor VIII deficiency

• D. Bernard-Soulier syndrome

A. Antiphospholipid antibody syndrome

A thrombus forms in the left atrium and embolizes to the brain. What type of embolism is this?

• A. Pulmonary thromboembolism

• B. Systemic thromboembolism

• C. Fat embolism

• D. Air embolism

B. Systemic thromboembolism

A postoperative patient with deep venous thrombosis suddenly develops dyspnea and pleuritic chest pain. Which event is most likely?

• A. Pulmonary thromboembolism

• B. Systemic arterial embolism

• C. Cholesterol embolism

• D. Tumor embolism

A. Pulmonary thromboembolism

After multiple long-bone fractures, a patient develops respiratory distress, neurologic symptoms, and petechial rash. What embolic material is most likely?

• A. Nitrogen gas

• B. Amniotic fluid

• C. Fat globules

• D. Tumor cells

C. Fat globules

A diver rapidly ascends and develops dyspnea, neurologic symptoms, and severe joint pain. Which mechanism explains the disease?

• A. Nitrogen gas emboli

• B. Fat emboli

• C. Platelet emboli

• D. Amniotic fluid emboli

A. Nitrogen gas emboli

A pregnant patient develops sudden dyspnea, DIC, and shock during labor. Which finding supports the diagnosis?

• A. Squamous cells and mucin in pulmonary vessels

• B. Cholesterol clefts in renal vessels

• C. Caseating granulomas

• D. Linear IgG along alveolar walls only

A. Squamous cells and mucin in pulmonary vessels

A pale, wedge-shaped renal infarct follows occlusion of an end artery. What type of infarct is this?

• A. Red infarct

• B. White infarct

• C. Septic infarct

• D. Venous infarct

B. White infarct

Hemorrhagic infarction is most expected in which setting?

• A. Kidney arterial occlusion

• B. Lung infarction with dual blood supply

• C. Spleen infarction from embolus

• D. Myocardial infarction without reperfusion

B. Lung infarction with dual blood supply

Gram-negative sepsis causes hypotension through LPS activation of Toll-like receptors. Which shock type is this?

• A. Cardiogenic shock

• B. Septic shock

• C. Hypovolemic shock

• D. Obstructive shock

B. Septic shock

A patient with major blood loss develops cool clammy skin, tachycardia, and hypotension. Which shock type is most likely?

• A. Hypovolemic shock

• B. Septic shock

• C. Neurogenic shock

• D. Anaphylactic shock

A. Hypovolemic shock

A patient with sepsis develops severe alveolar-capillary damage and hypoxemia. Histology shows hyaline membranes. What lung process is present?

• A. Chronic bronchitis

• B. ARDS / diffuse alveolar damage

• C. Pulmonary hypertension

• D. Bronchiectasis

B. ARDS / diffuse alveolar damage

A premature infant develops respiratory distress because surfactant production is inadequate. Which cell normally produces surfactant?

• A. Type I pneumocyte

• B. Type II pneumocyte

• C. Alveolar macrophage

• D. Clara cell only

B. Type II pneumocyte

A neonate with RDS has collapsed alveoli and eosinophilic hyaline membranes. Which surfactant component is most abundant?

• A. Phosphatidylcholine

• B. Cholesterol ester

• C. Sphingomyelin only

• D. Ceramide

A. Phosphatidylcholine

A smoker has chronic productive cough for at least 3 months in 2 consecutive years. What is the diagnosis?

• A. Emphysema

• B. Chronic bronchitis

• C. Bronchiectasis

• D. Asthma

B. Chronic bronchitis

A long-term smoker has enlarged mucous glands in bronchi. Which index is increased?

• A. Reid index

• B. Apgar index

• C. Gleason index

• D. Breslow index

A. Reid index

A patient with α1-antitrypsin deficiency develops emphysema predominantly in lower lung zones. Which pattern is expected?

• A. Centriacinar

• B. Panacinar

• C. Paraseptal

• D. Irregular

B. Panacinar

A smoker develops emphysema most severe in upper lobes and respiratory bronchioles. Which pattern is expected?

• A. Centriacinar

• B. Panacinar

• C. Diffuse alveolar damage

• D. Bronchiectatic

A. Centriacinar

A patient has episodic wheezing with mucus plugs containing Curschmann spirals and Charcot-Leyden crystals. Which disease is most likely?

• A. Bronchial asthma

• B. Chronic bronchitis

• C. Idiopathic pulmonary fibrosis

• D. Pneumoconiosis

A. Bronchial asthma

A patient has permanent dilation of bronchi due to chronic necrotizing infection and obstruction. What is the diagnosis?

• A. Bronchiectasis

• B. Emphysema

• C. ARDS

• D. Atelectasis

A. Bronchiectasis

A child with RSV infection shows diffuse interstitial infiltrates rather than lobar consolidation. What pneumonia pattern is most likely?

• A. Viral interstitial pneumonia

• B. Lobar bacterial pneumonia

• C. Cavitary tuberculosis

• D. Abscess only

A. Viral interstitial pneumonia

A patient aspirates oropharyngeal contents while intoxicated and develops a lung abscess with foul-smelling sputum. Which organisms are most likely?

• A. Anaerobic oral flora

• B. Mycoplasma only

• C. RSV only

• D. Pneumocystis jirovecii only

A. Anaerobic oral flora

A lung lesion shows caseating granulomas with Langhans giant cells. Which infection is most likely?

• A. Mycobacterium tuberculosis

• B. RSV

• C. Influenza

• D. Coronavirus

A. Mycobacterium tuberculosis

A patient has hemoptysis and renal failure. Antibodies target the α3 chain of type IV collagen in alveolar and glomerular basement membranes. What is the diagnosis?

• A. Goodpasture syndrome

• B. Idiopathic pulmonary hemosiderosis

• C. Sarcoidosis

• D. Silicosis

A. Goodpasture syndrome

A lung biopsy shows scattered poorly formed granulomas, capillaritis, and hemoptysis in a suspected ANCA-associated disease. Which diagnosis is most likely?

• A. Granulomatosis with polyangiitis

• B. Goodpasture syndrome

• C. Chronic bronchitis

• D. Asbestosis

A. Granulomatosis with polyangiitis

A shipyard worker develops pleural plaques and ferruginous bodies with beaded, dumbbell-shaped iron coating. Which exposure is most likely?

• A. Silica

• B. Asbestos

• C. Coal dust

• D. Beryllium

B. Asbestos

A miner exposed to silica has increased risk of which infection?

• A. Tuberculosis

• B. RSV

• C. Influenza only

• D. Candida pneumonia only

A. Tuberculosis

A smoker develops a central lung tumor with keratin pearls and intercellular bridges. Which carcinoma is most likely?

• A. Squamous cell carcinoma

• B. Adenocarcinoma

• C. Small cell carcinoma

• D. Carcinoid tumor

A. Squamous cell carcinoma

A peripheral lung tumor in a nonsmoker forms glands and produces mucin. Which tumor is most likely?

• A. Adenocarcinoma

• B. Squamous cell carcinoma

• C. Mesothelioma

• D. Large cell carcinoma

A. Adenocarcinoma

A patient with asbestos exposure develops a malignant tumor encasing the lung and arising from pleura. Which tumor is most likely?

• A. Mesothelioma

• B. Adenocarcinoma

• C. Small cell carcinoma

• D. Hamartoma

A. Mesothelioma

A child presents with nephrotic syndrome, selective proteinuria, normal light microscopy, and steroid responsiveness. Which diagnosis is most likely?

• A. Minimal change disease

• B. Membranous nephropathy

• C. Diabetic nephropathy

• D. Rapidly progressive GN

A. Minimal change disease

A renal biopsy from minimal change disease is examined by electron microscopy. Which finding is expected?

• A. Subepithelial humps

• B. Diffuse effacement of foot processes

• C. Linear IgG deposition

• D. Nodular mesangial sclerosis

B. Diffuse effacement of foot processes

A child develops nephritic syndrome 2 weeks after streptococcal pharyngitis. Which electron microscopy finding is classic?

• A. Subepithelial humps

• B. Foot process effacement only

• C. Linear IgG deposition

• D. Basket-weave GBM

A. Subepithelial humps

A boy has recurrent hematuria within days of sore throat episodes. Which immunofluorescence pattern is most expected?

• A. Mesangial IgA deposition

• B. Linear IgG deposition

• C. No immune deposits

• D. Subendothelial wire loops only

A. Mesangial IgA deposition

A young man has hematuria, hemoptysis, and rapidly progressive renal failure. Immunofluorescence shows linear staining along GBM. Which antibody is present?

• A. Anti-glomerular basement membrane antibody

• B. Anti-dsDNA antibody

• C. Anti-PLA2R antibody

• D. Anti-streptolysin O antibody

A. Anti-glomerular basement membrane antibody

A patient with SLE has severe renal disease with diffuse proliferative glomerulonephritis. Which immune pattern is typical?

• A. Full-house immunofluorescence

• B. Linear IgG only

• C. No immune deposits

• D. IgA only in mesangium

A. Full-house immunofluorescence

A diabetic patient develops nephrotic syndrome and nodular glomerulosclerosis. What are the nodules called?

• A. Kimmelstiel-Wilson nodules

• B. Aschoff bodies

• C. Psammoma bodies

• D. Councilman bodies

A. Kimmelstiel-Wilson nodules

A patient with nephrotic syndrome has diffuse capillary wall thickening and spike-and-dome appearance. Which diagnosis is most likely?

• A. Membranous nephropathy

• B. Minimal change disease

• C. IgA nephropathy

• D. Poststreptococcal GN

A. Membranous nephropathy

A patient has focal segmental glomerulosclerosis. Which phrase best defines the lesion?

• A. All glomeruli entirely affected

• B. Some glomeruli affected and only parts of affected glomeruli scarred

• C. Only tubules are affected

• D. Only the renal pelvis is scarred

B. Some glomeruli affected and only parts of affected glomeruli scarred

A diabetic woman with fever, flank pain, pyuria, and leukocyte casts has renal infection. Which diagnosis is most likely?

• A. Acute pyelonephritis

• B. Minimal change disease

• C. Membranous nephropathy

• D. Renal cell carcinoma

A. Acute pyelonephritis

A patient with acute pyelonephritis develops necrosis of renal papillae. Which clinical setting is strongly associated?

• A. Diabetes mellitus

• B. Minimal change disease

• C. IgA nephropathy

• D. Autosomal dominant polycystic kidney disease only

A. Diabetes mellitus

An adult with bilateral enlarged cystic kidneys, hypertension, hematuria, and family history has an increased risk of subarachnoid hemorrhage. Which associated lesion explains this risk?

• A. Berry aneurysm

• B. Charcot-Bouchard microaneurysm

• C. Aortic coarctation

• D. Pulmonary embolus

A. Berry aneurysm