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: THE "SKY" IS FALLING 
Clue: America's first space station
[EX A]: skylab

[EX Q]: Category: PRESIDENTIAL NICKNAMES 
Clue: "Butcher from Galena"
[EX A]: grant

[EX Q]: Category: ACCIDENTAL INVENTIONS 
Clue: In 1879 a chemist's unwashed hands got residue on a roll, which tasted sweet; he'd patent this, 300x sweeter than sugar
[EX A]:
saccharin