It’s very hot today, isn’t it—Yes, it is. Why not __________ your coat

下列各句中，加线的成语使用恰当的一项是（ ）

Catherine, I have cleaned the room for you . — Thanks. You_______. I could manage it myself.

观察下面4个选项,从中选出不同类的选项。

Someone called me up in the middle of the night, but they hang up ____ I could answer the phone.