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


[Q]: fax, file, format, image, document
[A]: fax


[Q]: down, ground, emotional upsets, backward, south
[A]:
emotional upsets