thank you very much for your answer.
Actually, in my work place I was told to ask all my questions from person B.
So, I used to ask all my questions from her and it was fine.
once I asked her a question (to follow up one of previous requests). Then, I was answered by “why don’t you ask person A (another person)”
I thought it is quite rude. As you said, I would have used another way of rejection!
So, I thought maybe it is not rude in the Australian culture. That is why I am asking it.