This is Must Be True question regarding "slavery" part of the passage.
Let's go to the answer choice straight away.
A) Whether they were prepared or not was not given. We are only given that rebellions were common but less collective.
B) Few of them owned MORE than hundreds worked, 2 percent to be exact. (25-28)
C) Unsupported. Management styles were different with the existence of intermediaries, but which was efficient was not dealt here. ...