C. Poe wanted to challenge social conformity and change the outlook on how people reacted to certain events. If you look a lot of his writing was dark and often gruesome. Do to this he was able to change the way writers transitioned their work, he also help classify the first detective workings as well as begin the science fiction genre.
The correct answer is the main idea
To be really honest, I think its a matter of opinion on which sentence is the strongest conclusion. To me, I think choice C is the best answer because it paints the contrast between the dog's wild instincts versus loyalty. I guess the conclusion should also mention that despite the abuse, Buck still learned to trust a human (even though one could easily understand why the dog would never trust a human after the abuse), so it shows just how powerful loyalty can be.
