What role did American government play in setting environmental policies during the 1970’s?

ANSWER: The resulting Clean Air Act of 1970 made EPA directly responsible for establishing limits on air pollutants and enforcing them. ... The agency eased into clean air issues slowly in order to give researchers time to do their work before legislative deadlines forced Ruckelshaus to promulgate air quality standards.

the answer would be:

b. race

an interest group is an organization whose members share common concerns, and try to influence government policies that impact those concerns. elected officials frequently complain about the influence of "special interests" on american politics.