The Environmental Defense Fund Hires Scientists, Economists, and Lawyers to Lobby

The Environmental Defense Fund hires scientists, economists, and lawyers to lobby the government and to educate the public about the environmental consequences of modern life. They brag that they had a part in passing important elements of the Clean Air Act, California's emissions rules, and a treaty to phase out CFCs. With what era of the environmental movement is this sort of organization MOST commonly associated?

A) the modern environmental movement
B) conservation environmentalism
C) Earth Day
D) mainstream environmentalism