Read the passage and choose the correct ones.I've got a brother who is two years older than I am. Sometimes he's OK but other times he is a real pain in the neck. I'll give you some examples. Yesterday I couldn't put the key in the front door because it was dark and I couldn't see where the keyhole was. Did my brother help? No, he just told me how stupid I was. And last week when I came back from the hairdresser's he took one look at me and laughed. "No boy will go out with you looking like that. But don't worry. I can help you. Here, take this paper bag and put it over your head." Have you any idea how I felt?On the other hand, having a big brother can be useful. My parents are not so worried about letting me go out at night as they would be if I were an only child. Another good thing is that all his friends are also two years older and there is one boy who I like very much and who is very good at math so when they all gather at our house, I make sure that I’m there and always have a problem with my math homework that only he can help me with. I hope he can help with more than my homework!
选项：

A:The writer is good at math.;
B:The writer is not good at math.;
C:The writer's parents are good at math.;
D:The friend of the writer's brother is not good at math.