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 consistency, answers should be in all lower cased letters.
PROBLEM: Category: ANAGRAMMED HITCHCOCK FILMS 
Clue: "Marine"

SOLUTION: "marnie"

PROBLEM: Category: AMERICAN EXPLORERS 
Clue: After being led there by a local, Hiram Bingham claimed he "discovered" this lost Incan city in Peru

SOLUTION: machu picchu

PROBLEM: Category: "DEC" THE HALLS 
Clue: Dr. Ludwig Roselius' research into this process led to the coffee brand Sanka in 1923

SOLUTION:
decaffeination