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: baby animals 
Words: cub, identity, buck, fawn, kid
identity

Category: computers 
Words: folder, document, file, image, correspondence
correspondence

Category: chocolate food 
Words: cake, fudge, rich, invent, cream

invent