instruction:
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.
question:
Category: WORLD HISTORY 
Clue: He completed vols. 2 & 3 of Karl Marx's "Das Kapital"
answer:
friedrich engels


question:
Category: PHOTOGRAPHERS 
Clue: In April 1875 the Library of Congress gained possession of his Civil War photographic plates for $25,000
answer:
mathew brady


question:
Category: VS. 
Clue: Juliet's family, they hate the Montagues
answer:

the capulets