In the context of Newton's law of gravity, what force is primarily responsible for the mutual attraction that drives the motion of massive objects such as planets and moons?

• A. The electrostatic force described by Coulomb's law $F=k\frac{q1q2}{r^2}$
• B. The frictional force proportional to the normal force $F=\mu N$
• C. The gravitational force described by $F=G\frac{m1m2}{r^2}$
• D. The buoyant force from a surrounding fluid as given by Archimedes' principle $F={\rho }_{f}gV$

Answer: (C)