Honestly don’t worry too much I got an E in my yr 12 mock for bio but after the summer holidays we had a resit exam. I did some solid revision over summer and ended up getting a B on the resit in September of yr 13 which got me an A predicted. Anyways UCAS admissions don’t close until end of jan in yr 13 so you have plenty of time to improve!
Personally, I think Accountancy is the easiest out of my three A-levels. You don’t really even have to be that good at maths like I thought you would have to be… It really just involves basic maths and remembering formulas. If you’re alright with that then Accountancy is quite easy.