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: VITAMINS & MINERALS 
Clue: The name of this vitamin is from the Latin for "leaf" because leafy green vegetables are a good source

SOLUTION: folic acid

PROBLEM: Category: CLASSICAL COMPOSERS 
Clue: The first movement of his 1868 first symphony is subtitled "Dreams of a Winter Journey"

SOLUTION: pyotr ilyich tchaikovsky

PROBLEM: Category: BIOGRAPHIES 
Clue: Carl Sandburg co-wrote a 1932 biography of this woman, "Wife and Widow"

SOLUTION:
mary todd lincoln