A: There is nothing free about Animal Farm. That is the whole point. Everything is recorded and used. A is wrong.
B: Boxer's response is very effective. Squealer is now in a position of power. Boxer would have been wise to say nothing, or act dumb (which he's done). B is not the best answer. Let's go on.
C: I think this is the best answer. Squealer is now on his guard. He says one thing that sounds like acceptance, but records another.
D. The point is that obedience is not enough. You have to be part of the inner circle of power and even then, you are not totally trusted. I think if you were writing an essay B and D could certainly be defended and commented upon, but your actual answer is still going to be C
C answer