Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Q: fret, angry, jack, nervous, emotionalities

A: jack
****
Q: prime, penalty, fine, mad, arrest

A: mad
****
Q: descending, south, kind, down, opposite of up

A:
kind
****