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

Answer: truss rod


Question: Category: outdoor sport activity 
Words: fish, hike, hunting, row, dog

Answer: dog


Question: Category: outdoor sport activity 
Words: climbing, fish, row, bat, camp

Answer:
bat