How did the feudal and manor systems promote a social hierarchy within medieval europe?

by eliminating the need for trade and a merchant class'

by encouraging the rise of artisans and guilds

by binding lower classes to specific tasks and roles

by tightening loyalties between vassals and lieges

I believe that the answer is C, "By binding lower classes to specific tasks and roles."

By binding lower classes to specific tasks and roles.

Explanation:

Through the development of rigid social institutions, such as the feudal and the manor systems, a strict social hierarchy was developed in Medieval Europe. In this hierarchy, people were not able to freely chose their professions and their place of living. Instead, most of their life was dominated by the specific tasks and roles that united them to a particular lifestyle from the moment they were born.