I want to stay here for another hour .----Ok.Remember __the door when you leave.

C
remember doing 记得做过某事，已发生
remember to do 记得去做某事，没发生

C

C.to close

remember to close the door when you leave.

走的时候记得关门。

remember to do something
记得去做

remember doing something
记得已经做过的事

C to close
remember to do记得去做某事(还没做)
remember doing记得做过某事(已做过)

C

A 表示过去 B 双谓语不可能 D同B

C表将来即将发生，正解