-- Its very hot outside.---Whyyou stay at home?A. not B. not to C. dont

问题补充：

-- Its very hot outside.

---Whyyou stay at home?

A. not B. not to C. don

答案：

解析：根据语境可知此句考查的是固定句型结构why don’t you do sth意思是为何不…表示的是建议相当于why not do sth。故选C。