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.

Category: secretary duty 
Words: schedule, file, answer calls, correspondence, ram
ram

Category: temperature 
Words: cold, hot, cool, popular, relaxing
popular

Category: chocolate food 
Words: unlicensed, chocolate, heavy, fudge, chocolate cake

unlicensed