I'll first explain some essential things about the education system in The Netherlands: At the age of ~12 you choose a level for further education, according to your intelligence. Roughly the 3 levels are: VMBO, HAVO & VWO. The smartest kids go to the VWO, which lasts six years. After those six years you'll have to pass for an exam. If you passed, you can study at an university.
One of the subjects is Maths. There are 4 levels available: Maths A, B, C, D. D is the hardest, B is hard, A is easy, C is the easiest (I know this sounds weird, but it is the truth). According to the university you need Math A. To make it even more complicated, you also have the choice to complete the whole subject, or only a part of it. If you complete the whole subject, it's called Maths A level 1,2. The other choice is Maths A level 1, which is only a part of Maths A.
I hope it's a bit clearer now!