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 simplicity, answers should be in all lower cased letters.

Q: Category: I GOT 3 As, MOM! 
Clue: In legend, this pure knight found the Holy Grail

A: galahad
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Q: Category: "PAR"TY TIME 
Clue: It's equal to 3.26 light years

A: parsec
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Q: Category: STAIR-ING AT THE SCREEN 
Clue: Robert Preston & Angela Lansbury starred in the film version of this 1957 William Inge play

A:
the dark at the top of the stairs
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