Who has the authority to regulate civilian aviation in the U.S.?

The correct choice identifies the Federal Aviation Administration (FAA) as the authority responsible for regulating civilian aviation in the U.S. The FAA is a branch of the Department of Transportation that oversees all aspects of American civil aviation, including safety regulations, air traffic control, and the certification of personnel and aircraft. Its primary mission is to ensure that the national airspace system operates safely and efficiently, making it the key regulatory body in this area.

The Department of Transportation plays a broader role in transportation policy and regulation but does not directly regulate aviation; instead, it encompasses various modes of transport, including highways, rail, and public transit.

The Drug Enforcement Administration and the Federal Bureau of Investigation are primarily focused on law enforcement and drug-related crimes, which have no direct role in the regulation of aviation. Their functions are unrelated to the oversight and management of civilian aviation operations in the United States.