What happens next in this paragraph?

The instructors wearing blue robes are showing the basic moves used in tai chi. They are swaying their hands above their heads from left to right. then the instructor
Select from the following.
I. demonstrates arm strength by tapping his right arm over his extended left arm..
II. turned around and walked back towards him and started and rubbed his face in his hand..
III. does the same tai chi move in the demonstrated..
IV. of the groups group is in the back demonstrating by doing a squat posture..
I.