Answer: Sit

The room is white and the stool on which the last person in the world is perched is black. Nothing else exists within the room. Another knock at the door, and a rush of wind hits the door. Just open it. They must be cold.

Answer: Open

Behind the door was no platform on which to stand, but a drop of about six feet to the grass covered ground below. A gust of wind enters through the door; silence is the only other reply.

Question

"The last person in the world sat in a room. There was a knock at the door. The question was: to open it or to remain seated?"