Final answer:
A ball squat, curl to press exercise belongs to the Strength level of the OPT model, aiming to improve stabilization endurance along with prime mover strength.
Step-by-step explanation:
A ball squat, curl to press is an exercise that involves multiple movements and requires the engagement of various muscles simultaneously. In the OPT model, which stands for Optimum Performance Training, this type of exercise would classify under Strength level. The Strength level is focused on enhancing the stabilization endurance while increasing the prime mover strength. This exercise incorporates both a stabilization component with the ball squat and a strength component with the curl to press motion.