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.
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Question: Category: ocean 
Words: current, data sets, main, sea, wave

Answer: data sets


Question: Category: social gathering 
Words: place, club, outing, lettuce, group

Answer: lettuce


Question: Category: location (proximity) 
Words: neighboring, right there, out of service, bordering, close

Answer:
out of service