The third one is the correct answer
They're both definitely unreliable, but the second answer(B) it doesn't seem like the narrator of "The Black Cat" seems insane, so I'm gonna think its D. I might be wrong though...
Douglass didn't grieve more when he learned that his mother had died because he had spent very little time with his mother.
He didn't manage to bond with her, and that is why her death did not strike him as sad as it would if they had been closer.