Which federal agency limits the number of radio stations in the United States?

The Federal Communications Commission (FCC) plays a crucial role in regulating and managing the airwaves in the United States. One of its primary responsibilities is to limit and allocate the number of radio stations to ensure that there is an orderly and efficient use of the electromagnetic spectrum. This helps to prevent interference between radio stations, maintain a diverse media landscape, and promote competition among broadcasters.

The FCC evaluates applications for new radio stations and enforces rules concerning licensing and frequency allocation. By doing so, the agency ensures that all broadcasters operate within a framework that promotes public interest and technological advancement. This systematic control helps to provide a balance between different types of communications services, including commercial and non-commercial broadcasting.

The other options, while relevant to specific areas of federal regulation, do not have the authority to set limits on the number of radio stations. The Federal Trade Commission, for instance, primarily deals with consumer protection and antitrust issues. The National Telecommunications Association is not a regulatory body but rather a trade association. The Department of Justice focuses on enforcing laws against antitrust violations and upholding national security, but does not regulate radio frequencies or station licensing.