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: WEIGHTS & MEASURES 
Clue: To the Ancient Greeks, 4 of these made a palm
[EX A]: fingers

[EX Q]: Category: PLANE CRAZY 
Clue: On August 6, 1945 this B-29 airplane became the first to drop an atomic bomb in warfare
[EX A]: the enola gay

[EX Q]: Category: PHILOSOPHERS 
Clue: The argument that the mind at birth is a blank slate is "key" to his 1690 "Essay Concerning Human Understanding"
[EX A]:
john locke