What Was a Fundamental Difference Between Slavery in Rome and Slavery

What was a fundamental difference between slavery in Rome and slavery in Greece?

A) Roman men could raise their children by female slaves as their legitimate children and heirs.
B) Greeks tended not to enslave other Greeks, but Romans preferred Italian-born slaves.
C) Roman slaves gained citizenship with their freedom, but Greek slaves did not.
D) Greek slaves had some legal protections against abuse, but Roman slaves did not.