Good morning,may I speak to Mark,please?A：Who's there?\x05\x05\x05B：Who's speaking?C：Who are you?\x05\x05\x05D：Who wants to speak to Mark?选哪个?

Good morning,may I speak to Mark,please?A：Who's there?\x05\x05\x05B：Who's speaking?C：Who are you?\x05\x05\x05D：Who wants to speak to Mark?选哪个?
Good morning,may I speak to Mark,please?
A：Who's there?\x05\x05\x05B：Who's speaking?
C：Who are you?\x05\x05\x05D：Who wants to speak to Mark?
选哪个?

Good morning,may I speak to Mark,please?A：Who's there?\x05\x05\x05B：Who's speaking?C：Who are you?\x05\x05\x05D：Who wants to speak to Mark?选哪个?
B 打电话时,不能用 you来询问对方,通常用Who's speaking?/
Who's that?/Who's that speaking?

B。 电话用语

B

选B