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: emotional status 
Words: nervous, frustrated, fret, jack, concerned

Answer: jack


Question: Category: physical activity 
Words: tumble, summer, fall, bend, lift

Answer: summer


Question: Category: shady activities 
Words: truffles, falsehood, fudge, invent, fib

Answer:
truffles