A. This statement is false, as the electromagnetic force between two protons is always greater than the gravitational force between them, because gravitational force is the weakest force in nature.

B. This statement is true, since electromagnetic force between two protons will be always greater than the gravitational force between them.

C. This statement is true, since, the gravitational force between two protons can be greater than the nuclear force between them as the nuclear forces depends upon the distance between the particles. If the distance is less, strong nuclear force will exist, else gravitational force will be stronger between the particles.

D. Electromagnetic force between two protons may be greater than the nuclear force acting between them. If the distance is less, strong nuclear force will exist, else electromagnetic force will be stronger between the particles.