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: aesthetic characteristic 
Words: pretty, probation, neat, fine, level
probation

Category: secretary duty 
Words: answer calls, image, organize, file, correspondence
image

Category: moral characteristic 
Words: fair, size, unprejudiced, decent, trustworthy

size