Amtrak, a company that provides passenger railway service, has been struggling financially and would like to stop service on its least profitable routes. Amtrak is usually relatively independent; it sets ticket fares and schedules, decides how to invest in new equipment, and is expected to generate enough revenue to cover expenses. However, the U.S. Congress stops it from cutting unprofitable service routes because, as a/an \________, part of Amtrak's purpose is to serve the entire country, even little-used rural passenger routes.