I think there are two reasons why a is better than D. First, we don't really know that the court ruling limited the right to SUE, but only that in one case the copyright holder lost their suit. We were never told that this ruling was actually precedential, nor that it limits the cause of action. They still can sue, but this ruling just might make it slightly harder for them to win.
A is much stronger because is more or less summarizes the reasons why the copy shop won.