It may involve the future postgraduate entrance examination. The later postgraduate entrance examination will be divided into mathematics one, two and three, which is inclusive. It is reasonable to say that mathematics A is the most studied, followed by B and C, with the largest range of mathematics, followed by II and III.
If you study math C, if you want to take the postgraduate entrance examination in the future, you should be optimistic about the outline of your major when you take the postgraduate entrance examination. If you take math I, you may have to teach yourself a lot.