【单选题】

Bill: Hello, Mary. Why are you standing here in the cold wind

Mary: ______, but buses are very full at this time of the day.
Bill: Where are you going This isn’t your way home.
Mary:But I’m not going home now. I’m going for a walk in the park.
A、I’m going home B、I’m going to work
C、I’m waiting for somebody
D、I’m waiting for a bus