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 consistency, answers should be in all lower cased letters.
question:
Category: 19th CENTURY BUSINESSMEN 
Clue: In 1873 he founded the J. Edgar Thomson works near Pittsburgh, naming the steel mill for the Penn. railroad president
answer:
carnegie


question:
Category: 3-LETTER WORDS 
Clue: For 5 & 7 it's 12
answer:
sum


question:
Category: THE IG NOBEL PRIZE 
Clue: An acoustics prize went to a study of why people hate the sound of fingernails interacting with this
answer:

a chalkboard