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: secretary duty 
Words: support, hardware, prepare, file, make coffee

Answer: hardware


Question: Category: secretary duty 
Words: correspondence, schedule, answer calls, keys, file

Answer: keys


Question: Category: employment activity 
Words: earth, sack, remove, fire, scold

Answer:
earth