1 December 2002 - train quiz

Today my commuter train rolled ever so slowly past a station with waiting passengers, continued at the same speed for a mile or so over a trestle, then stopped. After a while the train backed up past the trestle, stopped again, then backed up to the station to let the people on. My ten-minute train ride took half an hour.

How do you explain this mystery?

A. They were testing whether the official explanation, “slippery rails”, would cause riots.
B. The brakes don’t work, and they don’t care. Wear your safety goggles.
C. Shh! Secret project! The less you know, the better.
D. There was a glitch in the time machine. But don’t worry, the space-time continuum is all patched up now.