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: MOZART & FRIENDS 
Clue: Mozart wrote a lovely motet for Venanzio Rauzzini, one of these specially treated singers
[EX A]: a castrato

[EX Q]: Category: BEFORE, DURING & AFTER 
Clue: The "holy" first pope is in this '60s folk trio also including this actress who was "America's Sweetheart"
[EX A]: pope peter paul and mary pickford

[EX Q]: Category: THE MYSTERIOUS EAST 
Clue: River whose headwaters are in the Tibet highlands & whose delta is just south of Ho Chi Minh City
[EX A]:
the mekong river