<span>The correct option is C. Gravity, and the complete sentence is: "The force of gravity is the force at which the Earth attracts another object towards itself". In fact, the force of gravity between two objects is given by </span><span> where G is the gravitational constant, m1 and m2 the masses of the two objects, r their separation. If we take the Earth as one of the two objects, then m1 represents the Earth's mass, m2 the mass of the object and r the distance between the center of Earth and the object, and F is the gravitational force at which the Earth attracts the object.</span>
Gravity is a force of attraction that endures within any two bodies, any two groups, any two particles. Gravity is not just the attraction among objects and the Earth. Gravity is a force pulling mutually all matter. The longer matter, the more gravity, so things that have a lot of material such as planets and moons and stars pull more firmly. Mass is how we estimate the amount of matter in something.