A、  B、  C、  C句子是询问为什么电话占线的Why疑问句。

When is the orientation for our employees?
(A)It starts at 9 o’clock.
(B)No, it was informative.
(C)They’re all fully employed.

Why is the telephone line busy?
(A)Yes, I told her you left a message.
(B)There were 15 people in line.
(C)Ms. Kimura is on a conference call.