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.

[EX Q]: Category: BOOKISH 
Clue: Her novel "One Fifth Avenue" offers more sex in the same city
[EX A]: bushnell

[EX Q]: Category: "W"HODUNNIT? 
Clue: He was the first U.S. president to be unanimously elected
[EX A]: george washington

[EX Q]: Category: FAMILIAR PHRASES 
Clue: This phrase meaning "to betray someone" came from slaves sent illegally via the Mississippi to New Orleans
[EX A]:
to sell them down the river