A student is sitting on a chair. One force that is acting on the student is the pull of gravity. According to Newton’s third law, there must be another force which is

A.     the upward push of the chair on the student.

B.     the downward force on the student.

C.     the downward push of the chair on Earth.

D.     the upward force on Earth.

D

The Newton’s third law pair of forces in this case is the gravitational force of the Earth acting on the boy and the gravitational force of the boy acting on the Earth.