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: geographical property 
Words: mountain, flat, hill, mansion, plain

Answer: mansion


Question: Category: secretary duty 
Words: support, type, file, software, answer

Answer: software


Question: Category: personal characteristic 
Words: freezing, calm, positive, cool, popular

Answer:
freezing