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: SPORTS FIRSTS ON THE FIRST 
Clue: On February 1, 1970 Dave Balon pulled off his first one of these in his pro hockey career
hat trick

Category: OH "BOY" 
Clue: Slang term for an American infantryman of WWI
doughboy

Category: GOING "KNOT"S! 
Clue: To marry

to tie the knot