What happens next in this paragraph?

A man in a black tank top does several roller blade tricks. A man in a blue shirt switches of doing tricks. they
Select from:
(I) continue to trade off showing their skills.
(II) flash one shirt at the camera and it gets very cloudy outside.
(III) cross the finish line.
(IV) are back to the same book-lined room that the man was in before.
(I)