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.

Category: emotional status 
Words: fret, truss rod, emotional upsets, sad, worried
truss rod

Category: ocean 
Words: current, wave, whirlpool, sea, data sets
data sets

Category: chocolate food 
Words: fudge, cupcake, cream, pie, lie

lie