Write the next sentence in the following story.

A group of friends are at someone's house playing beer pong. they

Possible answers:
1). hit the ball back and forth, trying to keep the ball away from the cup.;
2). are surrounded by some sort of protective net.;
3). are having a really good time taking their shots and trying to win.;
4). finish and we see their dad in the picture.;. The answer should be
3).