Which of the following is an example of a medieval guild?

A- Monks who made agreements to provide an education to townspeople in exchange for food and shelter
B-Merchants with common trade interests who joined together and formed associations for their mutual benefit
C- Peddlers who traveled as a group to the same area to sell merchandise together rather than compete with each other
D-Vassals who united to pay taxes to their feudal lords with money, as well as crops and goods from their estates