The correct response is:
Earth’s gravity causes both objects to fall at the same rate.
In a vacuum (without air resistance), all objects fall at the same rate due to the acceleration of gravity, which is approximately 9.8 m/s², regardless of their mass. In the presence of air, lighter objects may experience more drag, but if we assume minimal effect from air resistance (as is often the case in typical scenarios), both objects will fall at the same rate due to gravity alone.