You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

Category: "ACTION"! 
Clue: For federal contracts, this 2-word employment term was first used in an order issued by JFK in 1961
affirmative action

Category: BRAIN STRAIN 
Clue: Appropriately, this stadium has hosted the NFL Super Bowl more than any other
louisiana superdome

Category: ENVIRONMENTALISM 
Clue: The world's first national park was Yellowstone, opened in 1872; this country opened its first park at Banff in 1887

canada