Newton's third law can be summarized as "every action has an equal and opposite reaction". In this problem, consider the action of the entire Earth on a person standing at rest on the ground and the opposite reaction, where ‘action’ and ‘reaction’ are understood to mean ‘force’ and ‘reaction force’

What is the "equal and opposite reaction force to the gravitational force of the Earth acting on the person?

(1) The contact force of the ground on the person, keeping them from traveling towards the center of the Earth.
(2) Since the person is not moving, there is no reaction force in this situation.
(3) The mutual gravitational interaction between the Earth and the person.
(4) The gravitational force, exerted by the person on the Earth.