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: CROSSWORD CLUES "D _ _ _ ER" 
Clue: Macbeth thought he saw one
[A]: a dagger


[Q]: Category: WHADDYA DRINKIN'? 
Clue: A Greyhound is vodka & this tart juice
[A]: grapefruit juice


[Q]: Category: CELEBRITY BOOKS 
Clue: This "Mad About You" star offered his witty views on marriage & living together in "Couplehood"
[A]:
paul reiser