Think about your personal capabilities/level of effort
It's really important that you know your own capabilities to judge how much effort you are able to put into studying a subject. If you're lazy and don't really care (although I don't recommend being like this in any case), then staying at a higher level might not be the best option for you, as studying a subject at higher level requires more work and concentration. Even if you are motivated and ready to put in the effort, it might prove pointless if your abilities just aren't up to it. Not every subject will suit you so don't just stay in a higher level subject you find hard just because you think you need to do everything in higher level. If you need extra tips/advice on how to study effectively, read the blog post here.