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.

[EX Q]: fearful, content, substance, program, thing
[EX A]: fearful

[EX Q]: flyaway, penalty, prime, fine, comfortable
[EX A]: comfortable

[EX Q]: instruct, fire, combustion, sack, let go
[EX A]:
combustion