Which of the Following Is True About the Clean Air

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

A) Congress set national ambient air quality standards for a number of pollutants.
B) Congress set goals,but not standards for a number of pollutants.
C) Congress directed the EPA to set ambient air quality standards for certain pollutants,but the EPA has not yet set the standards due to scientific uncertainty.
D) Congress directed the EPA to set ambient air quality standards for certain pollutants,and standards have been set thus far for carbon monoxide and sulfur oxide,among others.
E) Congress ordered the states to set ambient air quality standards,and most states have thus far set at least some ambient air quality standards.