Which of these statements concerning serfs in the feudal era is correct?
a. they had more rights than peasants.
b. many fought in service of their knights.
c. some saved enough money to move to other lands.
d. wealthy vassals often sold them to other vassals.

The statement which is correct about serfs from the feudal era and feudal ages was that some serfs could be sold to other vassals - when a wealthy vassal - who was also the lord of a manor - wanted new serfs or wanted to sell his serfs, he could do this and the serfs would be sold.

D is the correct answer.