I'm not sure if I'm missing rules or what but I can't seem to figure out how A B and C can be distinguished. I know D can be tossed out right away however.
I agree with Isaac. I think it is B. (almost 100%).
If you fold it and orientate it so the white face is showing, you should have two shaded regions on the sides NOT one. (One would be on the top, which A has, and one directly next to it)