Situation: Speaker A is praising Speaker B for his good Chinese.
-You speak very good Chinese!
-________. I have been studying Chinese for a few years.

选择一项：
a. Thanks 解析：前者称赞后者中文很好，面对他人的称赞，遵循礼貌原则要先感谢对方，只有Thanks是表示感谢的。
b. I don’t know.
c. It must be hers.
d. I am sure.