Yo, well in politics I got a C at AS then re-sat the exam and got an A. So that's two grades, an example that it is possible. I also did economics, and whilst I think it's a pretty heavy subject, it is 100% possible to push that grade up to a C or B with hard work. I'd go about making a list of all the subject content then highlighting the stuff you don't know, revise from your textbook and get clued up. I'd give it a guess and say in your A2 you'd need a high B to get an overall of a C, which is hard to do! Really best of retaking and giving it your all so you have the foundations for the A2 exams in my opinion!