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 consistency, answers should be in all lower cased letters.

Category: RED ROVER, RED ROVER 
Clue: This NASA "Lab" based in Pasadena designed the rovers used on Mars
jpl

Category: THE THEATRE 
Clue: Playwright Jean Anouilh had a lot at "stake" with "L'Alouette", his play about this female saint
joan of arc

Category: BANDS IN OTHER WORDS 
Clue: Ebony Sunday

black sabbath