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.

[Q]: Category: CINEMA 
Clue: Vangelis' theme from this 1981 British film took a record 21 weeks on the charts to reach No. 1
[A]: "chariots of fire"


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


[Q]: Category: FERROUS, BUELLER 
Clue: An olden theory said that when metallic iron loses its phlogiston, it becomes this remnant we know as an oxide
[A]:
rust