If it makes you feel better, I know I've definitely lost 4 marks. But excluding the option topic cause I didn't study for it. I studied for the MRI and PET scans but not the CAT and x-rays cause I thought they were easy, and I couldn't remember I single thing in the exam and had to make up crap.
Based on what I've written, if i get above 15/25 I should thank God!
So if I get lucky = 80+
If I pray hard enough = 85