A is a steep or about 45° angle while B appears to be a straight down angle of 0°. So if you take that into account, if you are subtracting A and B, it would be around in between. It will probably not be backwards because neither is facing to the left except the answer choices so B is wrong (the answer B).
R is even steeper than before, and if you are subtracting, it would probably be C.
