Newton Concluded That a Force from the Earth Had to Act

Multiple Choice

Newton concluded that a force from the Earth had to act on the Moon because

A) a force is needed to keep the Moon in motion in its orbit.
B) a force is needed to pull the Moon outward.
C) a force is needed to accelerate the Moon toward Earth away from straight-line motion.
D) the Moon moved at a constant velocity in a straight line.
E) All of the other choices are correct.