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.

Category: "AIN" WE GOT FUN 
Clue: Shiites are dominant in this Qatar neighbor
bahrain

Category: A NATION DIVIDED 
Clue: It was officially divided into North & South in 1953
korea

Category: PEN NAMES 
Clue: This pseudonym means "2 fathoms deep"

mark twain