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: GO WITH THE FLOW 
Clue: The Tigris flows into this gulf
[A]: the persian gulf


[Q]: Category: LITERATURE 
Clue: George Du Maurier introduced this evil hypnotist in his 1894 novel "Trilby"
[A]: svengali


[Q]: Category: "HOW" NOW 
Clue: "Smokestack Lightnin'" was the biggest hit for this bluesman born Chester Burnett
[A]:
howlin\' wolf