Question

Who replaced slaves in Europe during the Middle Ages?

A: Artisans
B: Clergy
C: Knights
D: Serfs

Answer 1

D. Serfs (Serfdom)

Step-by-step explanation:

Slavery became uncommon through the Middle Ages which was replaced by serfdom by the 10th century, but began to revive again towards the end of the Middle Ages and in the Early Modern Era.

Main source - (Wikipedia)

Hope this helps.