Did either of the sisters bring her umbrella?
Either is singular.
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.
I believe he thought we couldn't controll Some of our choices, however that is flase, because in our to make a choice between things, you must think about it in order to come up with a choice.
Ego and superego is basically Just how you come off if that makes sense.They really couldn't control your choices.