Which Statement(s)about the Clean Air Act Is/are TRUE

Which statement(s) about the Clean Air Act is/are TRUE?

A) The Clean Air Act is evidence that regulations can be effective as a pollution-reduction tool because the United States has seen major reductions in common air pollutants.
B) Under the Clean Air Act,the EPA sets air quality standards for ambient air,with the states being responsible for monitoring and enforcing compliance.
C) The Clean Air Act is subject to political wrangling,as evidenced by the introduction of several congressional bills designed to limit the EPA's ability to regulate air quality,specifically carbon dioxide (CO₂) .
D) Under the auspices of the Clean Air Act,the EPA approved greenhouse gas emission standards for light-duty vehicles (cars and trucks) that will require new vehicles to produce less greenhouse gas emissions.
E) All of these answers are true.