What happens next in this paragraph?

They start taking turns in front of the mirror trying to perfect their moves. They are doing all kinds of crazy acrobatic flips and other moves. there
Select from:
[I] is about six or seven men sitting up against the wall watching as the other flips around in the air.;
[II] is a man in the back while a female is standing in front of him.;
[III] are marks into the mirror where they will meet with one another for a real workout.;
[IV] are also some shady handstands being brushed by the girls.;
[I]