The correct option is B.
In the book, we were made to understand that, Frederick Douglass' master lend Douglass to Mr Covey when he considered him no longer manageable, so that Mr Covey will tame him.
Mr Covey is a poor white farmer, who has reputation for been an expert at breaking slaves and taming them; he was a very cruel master and he treated Douglass so badly that he had to fight back and make plans about how to run away.