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: EXPLORERS 
Clue: John Speke died just before he was to debate this former exploring partner on the source of the Nile
sir richard burton

Category: GOOD SPORTS 
Clue: In 2006 this team's David Ortiz was wicked excellent with 54 HRs & 137 RBIs
the boston red sox

Category: WHO'S THE ARTIST? 
Clue: A neo-classicist, this artist often painted the high & mighty

jacques-louis david