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: chocolate food 
Words: rich, chocolate, fudge, chocolate cake, unwarranted

Answer: unwarranted


Question: Category: secretary duty 
Words: answer calls, file, correspondence, document, fax

Answer: document


Question: Category: social gathering 
Words: club, convention, cinema, open-faced, clan

Answer:
open-faced