A、A man. B、A woman. C、A boy. D、A girl. A

W: Hello.
M: Hello, is this John Smith’s home?
W: Yes, it is, but he is out right now. Would you like to leave a message?
M: Well, I really don’t know what I should do. I can’t ask him to call me back because I’m calling from a friend’s.
W: Well, then, why don’t you try his office? I think he’s there now.
M: Yes, I guess I could do that.
W: Would you like to have the number?
M: That would be very kind of you.
W: His office number is 11123345 . You can reach John there.
M: Thank you so much for your help.
W: You’re welcome. Goodbye and good luck.
Who is calling John Smith?