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: TO REMAIN "SILENT" 
Clue: Quiet alliterative nickname of the U.S. Navy's submarine fleet

A: the silent service
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Q: Category: FICTIONAL DETECTIVES 
Clue: "The House Without a Key" was the first case solved by this Chinese detective

A: charlie chan
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Q: Category: SAME FIRST & LAST LETTER 
Clue: An invisible emanation, or an intangible quality

A:
aura
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