How did the formation of a middle class affect peasants during the Middle Ages?

A- Peasants had an opportunity to move up in the social hierarchy by becoming artisans, merchants, or other types of professionals.
B- Peasants had fewer opportunities to influence the economy or the government because only the upper class could become members of the middle class.
C- Peasants found themselves in an even lower position than before, as more people made up the upper and middle classes.
D- Peasants who had previously been in the lower class automatically moved up to the middle class, allowing them to obtain high social and political positions.