gsce resit

It really depends on your confidence levels. If you resit an exam, you can always choose the better grade, so there's no risk of "making your grade worse". On the other hand, you may not want to waste time on other subjects and focus on the ones you need to pass. In terms of "limiting your options", this really depends on what your options even are.
Also, I would post this in the GCSE forum instead of the A-level forum.