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: GOVERNMENT AGENCIES 
Clue: The Centers for Disease Control & Prevention is an agency of this department

SOLUTION: health and human services

PROBLEM: Category: "PAR"TY TIME 
Clue: It's equal to 3.26 light years

SOLUTION: parsec

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

SOLUTION:
mosaic