Which agency administers the regulations under the Clean Air Act?

The Environmental Protection Agency (EPA) is the correct answer, as it is the agency specifically tasked with administering and enforcing the regulations set forth under the Clean Air Act. The Clean Air Act is a significant piece of legislation aimed at controlling air pollution on a national level, and the EPA is responsible for establishing and enforcing air quality standards, implementing programs to reduce air pollutants, and ensuring compliance among affected industries.

The other agencies listed are involved in different areas of regulation. For instance, the Occupational Safety and Health Administration (OSHA) focuses on ensuring workplace safety and health, which does not cover air quality management. The Federal Trade Commission (FTC) primarily oversees consumer protection and antitrust issues, while the Department of Labor (DOL) is responsible for labor regulations and workforce issues rather than environmental concerns. As such, their mandates do not intersect with the specific responsibilities outlined in the Clean Air Act, reaffirming the EPA's role as the principal authority on this matter.