['I was expecting to get a low B or even a C in one of my hardest university courses. Instead, on the Final Exam there was bonus opportunity to which I came out with an A average.']
Nice, I bet you feel so relieved!
I had a low average in one of the harder courses in my bachelor's program. It was not looking good until the final exam had bonus opportunities. After receiving my scores, I was able to achieve an A in the course.