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.

[EX Q]: Category: SEX CHANGES 
Clue: Don't let the pearls fool you, these lady bivalves can change into males when it suits them
[EX A]: oysters

[EX Q]: Category: BODY LANGUAGE 
Clue: When vou're idle or just plain bored, you do this with your pollex digits, literally or figuratively
[EX A]: twiddle your thumbs

[EX Q]: Category: GRAINS & STAPLES 
Clue: The name of this food, not a true grain, comes from the Dutch meaning "beech wheat"
[EX A]:
buckwheat