have you updated to the latest version?
I had a discussion with them over this question as generally they do not "nitpick" as much on other problems. They supposedly fixed it so it will obviously be B rather than A. I no longer use the program so I didn't update to the latest or the version with it corrected so I can't attest to this fact or not. I would assume they corrected it based on change logged.
If you're worried about losing your scores then the reason why it is B and not A because note the face. that diagonal dash mark. In A it is not the correct length as the unfolded. its too short.
you can get a question like this on the exam where amount of shading/length of marks makes a difference in the answer.