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.

[EX Q]: Category: 20th CENTURY NOVELS 
Clue: Manfred de Spain appears in "The Town", "The Mansion" & "The Reivers" by this author
[EX A]: faulkner

[EX Q]: Category: DRAMA 
Clue: Sula & Helena are robotesses in this Karel Capek play
[EX A]: "r.u.r."

[EX Q]: Category: A VISIT WITH SHERLOCK HOLMES 
Clue: When Watson met Holmes in a lab, Holmes explained his test for this pigment--it could have decided several cases
[EX A]:
hemoglobin