问题补充：
—Mom, this is my new friend, Jack.
— .
A. OK
B. Thank you
C. Nice to meet you.
D. You are very good.
答案：
A. OK
B. Thank you
(答案→)C. Nice to meet you.
D. You are very good.
解析：OK好吧；Thank you谢谢你；Nice to meet you.很高兴遇到你； You are very good.你非常不错。根据上文，妈妈，这是我的新朋友，杰克。可知选C，最符合语境。
