TASK DEFINITION: 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.
PROBLEM: Category: HOW GREAT THOU ART 
Clue: This "mama's boy" answered the art critics in his 1890 book "The Gentle Art of Making Enemies"

SOLUTION: whistler

PROBLEM: Category: GLAND FINALE 
Clue: This human gland important in the immune system takes its name in part from its resemblance to an herb

SOLUTION: the thymus gland

PROBLEM: Category: SPORTS RULES, MAN! 
Clue: In this track & field event, a 45-meter-long runway can front a 9-meter-long moistened sandpit

SOLUTION:
long jump