Why Was the Institution of Slavery a Barrier to Technological

Why was the institution of slavery a barrier to technological change in the Roman Empire

A) There was no incentive for slave owners to introduce technological change to work processes, since the slaves would reap all of the benefits from the reduced hours and easier work.
B) There was no incentive for slaves to adopt technological change in work processes, since the intensity of their work would not improve.
C) Roman Law prohibited the introduction of technological change into work processes.
D) Most technological change was too expensive for slave owners to purchase.