What happens next?

Two boys walk down a sidewalk near a pool. There are lots of people doing different things in and around the pool. some boys

Available options:
[a]. swim back and fourth down the sidewalk.;
[b]. are performing different tricks using cat paddles.;
[c]. jump off of the diving boards doing flips and other tricks.;
[d]. are playing on a low diving board.;
[c].