—You are wearing a blue dressHow beautiful it is!—A. I am glad to hear that.B. Thank you.

问题补充：

—You are wearing a blue dress．How beautiful it is!

—

A. I am glad to hear that.

B. Thank you.

C. Really?

D. Not at all.

答案：

A. I am glad to hear that.

(答案→)B. Thank you.

C. Really?

D. Not at all.

解析：I am glad to hear that.很高兴听你那样说;Thank you.谢谢你;Really?真的吗;Not at all.一点都不.根据上文,你穿着一件蓝色的连衣裙.它太漂亮了. 英语中对于别人的祝福，夸赞的回应一般是表示感谢。故选B。