I will only opt for re-writing the exam if I know that what I did in the previous one is nothing to fetch me a desired score maybe as a result of something else that came up during my preparation for the exam and would have done better but 4 my un-preparedness and I'm sure if allowed to retake it, will surely performed better. But if it is the other way round prolly a course I hate or find very difficult to understand, would just opt for the general score