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: U.S. GOVERNMENT 
Clue: This group that first met in 1942 didn't get a permanent chairman until 1949
[EX A]: the joint chiefs of staff

[EX Q]: Category: HISTORIC AMERICANS 
Clue: He turned down an appointment as a U.S. senator in 1875 because it meant accepting a pardon for treason
[EX A]: jefferson davis

[EX Q]: Category: IN THE DICTIONARY 
Clue: This 5-letter word can refer to one type of work by a composer, or to several works of different types
[EX A]:
opera