Which of the Following Statements Is True of the Clean

Which of the following statements is true of the Clean Air Act?

A) Air quality standards are set federally,but the states are required to establish implementation plans to achieve and maintain those standards.
B) Private companies receiving federal contracts,funding,licenses,and the like may be parties to the completion of an environmental impact statement.
C) Limits are imposed on the amount of pollutants that may lawfully enter the water of the United States from any "point source."
D) All pollutant dischargers are required to secure an Environmental Protection Agency permit before releasing effluents into a navigable stream.