In Newton's law of universal gravitation, which two quantities determine the magnitude of the gravitational force between two point masses separated by a distance $r$?

• A. The masses of the objects and their velocities relative to each other
• B. The electric charges of the objects and the separation distance $r$
• C. The two masses ($m$ and $M$) and the separation distance $r$
• D. The masses of the objects and the temperature of the surrounding medium

Answer: (C)