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: MUSICAL THEATER 
Clue: In France, this musical was known as "Brillantine"; in Mexico, it was "Vaselina"
[A]: grease


[Q]: Category: HISTORIC NAMES 
Clue: 2 of the people who witnessed his execution were John Wilkes Booth & Stonewall Jackson
[A]: john brown


[Q]: Category: MATH WORDS 
Clue: In Latin the name of this math field meant a pebble used in counting, & the word also has the medical meaning "stone"
[A]:
calculus