instruction:
Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.
question:
Category: physical property 
Words: brittleness, protein, bulky, skinny, fat
answer:
protein


question:
Category: employment activity 
Words: sack, inferno, promote, empower, fire
answer:
inferno


question:
Category: aesthetic characteristic 
Words: fair, light, even, clime, size
answer:

clime