What Is the Primary Difference Between a Caste System and Slavery

Multiple Choice

What is the primary difference between a caste system and slavery?

A) Slaves are not able to move into different classes, whereas caste members can do this.
B) Slaves are owned, whereas caste members are not.
C) Slaves may be bought and sold, whereas caste members may only be given away.
D) Slaves may have contact with others who are not slaves, whereas caste members may not contact those of a different caste rank.