This is a test of commonsense with single/multi-choices. Complete the next sentence:

People are seen riding around on skateboards past one another. people

Choose from: --watch on the side as one makes turns around.. --look and smile to the camera while continuing to ride around a city on skateboards.. --are then shown riding over a large-sized hill on a tube.. --position themselves on top of exercise bikes..
The answer is:
look and smile to the camera while continuing to ride around a city on skateboards.