Question

-Did the teacher tell you ________ next week?

-Yes. We'll visit the Great Wall.

1. A.
   to go where
2. B.
   how to do
3. C.
   what to do
4. D.
   to do what

Answer 1

C
动词不定式可以和疑问词what，which，how，where，when等词连用，构成不定式短语，但整个句子仍为简单句。如：Do you remember how to do it?
拓展延伸：这种简单句可以还原为复合句。如：
I don't know what to do next.
→I don't know what I should do next.