听力原文：W What are you doing sitting in the dark？ Why don't you turn on the light？
M I had it on, but it just turned off a few minutes ago. I figured the electricity had gone out in the building. W No, these lights go off in half an hour if they detect no movement in the room. To turn them back on, all you have to do is wave your arms.
M You're kidding! I didn't even budge when the lights went out. I suppose if I had gotten up, I would have figured out what was going on.
Why is the woman surprised？

A. The office is unlocked.
B. The office is very cold.
C. The man is sitting in the dark.
D. The man is leaving the office early.