Final answer:
The reaction force to the Earth's gravitational pull on a falling ball, according to Newton's Third Law, is the force the ball exerts on the Earth.
Step-by-step explanation:
As a ball falls, the action force is the pull of the earth's mass on the ball. According to Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction, the reaction force would be the force exerted by the ball on the earth. This law explains interactions such as the Earth pulling on the moon and the moon pulling on the Earth, a person standing on Earth applying a force on the Earth as the Earth applies a force on the person, or a rocket pushing on gas and the gas pushing back on the rocket. Therefore, the correct answer is (3) force exerted by the ball on the earth. This can be understood further by the fact that field forces like gravity can act without direct contact, and they are experienced by bodies within the field. Gravity, being a field force, acts between the Earth and the ball without direct contact, and similarly, the ball's gravitational attraction acts on the Earth.