When you want to establish business relations with your potential潜在 customers, you should tell the receiver:
选项：

A:how his name is known 如何得知他的信息
B:what you handle 你做什么生意
C:what you want to do, that is, what you want to sell or what you want yo buy 你想要的买卖的东西
D:you are looking forward to his early reply 期待他的答复