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: 4-LETTER WORDS 
Clue: 4-letter Italian term for the boss of a crime syndicate
[A]: a capo


[Q]: Category: SUN 
Clue: In the main reaction making the sun's energy, 2 of these nuclear particles fuse & one becomes a neutron
[A]: protons


[Q]: Category: PRESIDENTIAL NICKNAMES 
Clue: The "Wizard of Kinderhook"
[A]:
van buren