Question

— Do you know _____?
— Next Sunday.

A．what they will do	B．where they will do
C．when they will come here	D．who they will meet

Answer 1

C

四个选项分别表示要做什么、要做哪儿（语义不通）、什么时候来这和他们要见谁。根据答语下个星期日，可知前文问的是时间，选C。