Other than asking what degree your a-level choices suit, think about what you WANT to do.
I know that may be a shadowy area at the moment, but don't rush into any decisions. You're still on your GCSEs so you have plenty of time yet before you decide what degree you want to do, if you even still want to go down that road when the time comes.
Think about what interests you and what you would be happy doing. You'll be spending a substantial amount of time and money on the degree, so make sure it's something you really want to do.
I'd recommend trying out a lot of different areas just to see what you like and don't like. Try talking to someone at your school about setting up a careers day or something, so you can ask/talk to a lot of people from different careers and see what interests you!
You have plenty of time yet, so don't worry too much about the future, knuckle down and get the best grades you can in your GCSEs and A-levels and see where they take you! A lot of people can't decide what they want to do while in education, and that's normal, especially at such a young age because you're always changing your mind. Allow room for experimentation to see what area of things you'd like to get into, then decide from there.