A man jogs down a city street , with a line attached to his back that vanishes out of the left side of the picture ; a smiling cyclist rides past .
It is certain that the line on his back has a parachute on it .
There is almost no chance that the line on his back has a parachute on it .
It is certain that the line on his back has a parachute on it .
The line on his back has a parachute on it .