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: VIDEO GAME HISTORY 
Clue: id Software says hardcore PC games went mainstream in 1994 when it unleashed this fatal-sounding game
doom

Category: "OCK" DU LIEBER 
Clue: This bird known for its mimicry is the state bird of 5 southern U.S. states

the mockingbird