Everyone is different, so I could be off base, but I really think that trusting in the Blind Review process is going to be your best bet here. Don't be afraid to spend a long time on each question distinguishing between the one correct answer and the four incorrect ones. What exactly is the question asking for, and does that answer choice actually fulfill that at all?

Additionally, if your problems really are with those last 5, create drills of questions with only those difficult ones for a little while and see what that does. Again, try not to be afraid to really spend a lot of time, and the speed will come.

I hope that this helps, even a little bit!