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 consistency, answers should be in all lower cased letters.

[EX Q]: Category: HOLIDAYS & OBSERVANCES 
Clue: Mexico defeated France at the Battle of Puebla on this date in 1862
[EX A]: fifth of may

[EX Q]: Category: ADVENTURES IN LITERATURE 
Clue: The epilogue of this novel says, "I have now told the singular, but veracious story of the opera ghost"
[EX A]: phantom of the opera

[EX Q]: Category: MEDICINE 
Clue: This medical field specializes in the diagnosis & treatment of heart disorders
[EX A]:
cardiology