English lit (which I do and love) or history would be good alternatives if you are looking to get into a more reputable uni, but perhaps psychology would be a good choice to go with biology- I do biology on it's own but if you only do one science/science-related subject for a level it's harder to get into a science-y degree, so I regret not doing chemistry/physics/science related subject like psychology too. However, psychology isn't too reputable, so you'd have to look into it. I would not do law as it's considered soft, the same goes for sociology. I personally hate maths so I wouldn't do it. But stick with media if it's relevant to the degree you want to do and if you love it.
Just actually read the first part properly, lol. It'd be a good idea to do chemistry instead of geography AND do something else in block A, BUT some of my friends do chemistry and it is ridiculously hard, so you'd have to think about it.
Hope this helps! If it was me, I'd probably:
A) change block A to psychology
Or
B) change block A to english lit/history and change block B to chemistry.