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.

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

Category: DUEL
Clue: In English-speaking countries, once a duel was accepted, this person chose the weapons to be used
the person being challenged

Category: ROCK'S FRONTMEN & WOMEN
Clue: Ozzy Osbourne
black sabbath