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: FAMOUS PAIRS 
Clue: Now meaning nearly identical, these 2 names were applied to rivals Handel & Bononcini in a 1720s British verse
[A]: tweedledum & tweedledee


[Q]: Category: WOMEN SINGERS 
Clue: The 411 on this R&B singer: her song "Be Without You" was No. 1 in 2006, & her middle initial J. stands for Jane
[A]: mary j. blige


[Q]: Category: NON-COSMETIC SURGERY 
Clue: Removal of the gallbladder is the usual treatment for concretions better known as these
[A]:
gallstones