— Sonia. Is this your backpack?—Yes it is. Thank you.A. SorryB. GoodbyeC. Excuse meD. OK

问题补充：

—, Sonia. Is this your backpack?

—Yes, it is. Thank you.

A. Sorry

B. Goodbye

C. Excuse me

D. OK

答案：

A. Sorry

B. Goodbye

(答案→)C. Excuse me

D. OK

解析：

选项A用于道歉；选项B用于告别；选项D表示同意；选项C用于打断别人的话，或询问等的礼貌用语。故选C.