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: EARLY ART 
Clue: This art form of setting stones or glass into mortar was the main decorative art of the Byzantine Empire
mosaic

Category: DAVID MAMET 
Clue: In 1976 Mamet taught at the School of Drama at this Ivy League university whose alumni include Meryl Streep
yale

Category: HEALTH & MEDICINE 
Clue: This is the most important of the androgens, or male sex hormones

testosterone