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.

Q: Category: TIME FOR A "CON"TEST 
Clue: Though it possibly dates from the 16th century, the origin of this word for a punny riddle is a mystery in itself

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

A: affirmative action
****
Q: Category: CANADIAN HISTORY 
Clue: Once the Canadian Pacific Railway reached this Alberta city in 1883, Settlers began a "stampede" to live there

A:
calgary
****