16 Two identical spheres are attached to opposite ends of a thin rod of negligible mass, as shown in the figure. The spheres-rod system is thrown straight upward and is rotating counterclockwise as it moves through the air. Which of the following is correct about the angular momentum of the spheres-rod system while it is in the air? What is a valid justification? А The angular momentum remains constant because there is never a net torque acting on the system. B The angular momentum remains constant because there is a changing net torque acting on the system that averages to zero over time. The angular momentum constantly decreases because there is a constant net torque acting on the system. The angular momentum constantly increases because there is a constant net torque acting on the system.​