B. A television show starts a new season
I think it is C, because if I'm right present principal is something that is happening presently? If so, C would be the answer because they "are doing" the exercises right now in context.
This is the Newton’s third law of motion buddy: If an object A exerts a force on object B, then object B must exert a force of equal magnitude and opposite direction back on object A. Hope it helps :D
