— I’m going to the Great Wall tomorrow.— Mike.A. Thanks a lot B. Enjoy yourself C. You a

问题补充：

— I’m going to the Great Wall tomorrow.

— , Mike.

A. Thanks a lot B. Enjoy yourself C. You are great

答案：

解析：Thanks a lot多谢；Enjoy yourself请自便，祝玩得愉快；You are great 你太棒了。根据上文，我明天打算去长城。可知选B最符合语境。