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: police punishment 
Words: prime, penalty, fine, mad, arrest

Answer: mad


Question: Category: shady activities 
Words: fib, replace, falsification, molasses, fudge

Answer: molasses


Question: Category: corporate 
Words: concerted, stiff, llc, combined, firm

Answer:
stiff