Write the next sentence in the following story.

How to do side planks with an exercise ball
Put your exercise ball in an open area.
You should have plenty of free space to move around, and all sharp/heavy objects should be removed so as to minimize the potential for accidents.
Kneel on an exercise mat with the exercise ball next to you.

Options are:
I. Keep your knees firmly planted on the mat and your knees lined up with the balls of your feet. Position your hips so they're above hip level.;
II. Keep your hands palm down and knees bent up. Put your entire right foot on the mat and perform a side plank step by step with your left foot.;
III. It doesn't matter which side the ball is on first since you'll eventually work out both sides for this exercise. Lower your upper body to drape over the exercise ball.;
IV. It's good for both feet. Balance your exercise ball mid-plank.;. The answer should be
III.