—Who has taken my pen away?—__________. He was here a moment ago

—Who has taken my pen away?
—__________. He was here a moment ago.
A、It must be Li Ping
B、It is Li Ping take
C、Li Ping is
D、Li Ping must take
【正确答案】：A
【题目解析】：本题是对情态动词的考查。句意表示肯定的推测用must，而it指问句中提到的who。 ​