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: HISTORIC QUOTES 
Clue: This great Prussian king is credited with saying, "An army, like a serpent, travels on its belly"
[A]: frederick the great


[Q]: Category: FICTIONAL DETECTIVES 
Clue: "The House Without a Key" was the first case solved by this Chinese detective
[A]: charlie chan


[Q]: Category: CALL ME ALEX 
Clue: He's the 19th century inventor seen here
[A]:
alexander graham bell