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.

[Q]: Category: construction 
Words: hoist, tackle, digger, excavator, crane
[A]: tackle


[Q]: Category: emotional status 
Words: truss rod, emotional supports, emotional upsets, emotionalities, fret
[A]: truss rod


[Q]: Category: computers 
Words: file, space, program, firewall, answer
[A]:
answer