Answer:
B. Slavery was based on race
Step-by-step explanation:
Indentured servitudes agreed to work in exchange for passage to America. It was a contract between two individuals. Anyone could become indentured servants, and was a way for people to afford coming from England to America.
Slavery did bring people to America for them to work, but slaves were given no choice because of the color of their skin. There was no contract between individuals; it was done completely against the slaves' will because of their race.