TASK DEFINITION: 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.
PROBLEM: Category: ANIMALS 
Clue: Buckskin was originally made from the mule & white-tailed species of this ungulate

SOLUTION: deer

PROBLEM: Category: MOTHER GOOSE 
Clue: It's the type of nail referred to in the nursery rhyme "All for Want of a Nail"

SOLUTION: a horseshoe nail

PROBLEM: Category: COMPLETES THE PROVERB 
Clue: "Promises are like pie-crust, made to be..."

SOLUTION:
broken