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: ROYALTY 
Clue: It's the name of today's longest-ruling family in Europe, in power for most of the last 711 years
grimaldi

Category: 1930s FILMS 
Clue: In this classic film, one of the characters tries to quote the Pythagorean theorem but gets it wrong
the wizard of oz

Category: WORD HISTORY 
Clue: Before this word came to mean an extraterrestrial, it was used as an adjective meaning "warlike"

martian