Why are large amounts of energy required to separate a nucleus into protons and neutrons even though the protons experience electrostatic repulsion? a. the forces holding the nucleus together are much stronger than the repulsion among the protons. b. the electrostatic forces acting among other atoms lower the force of repulsion of the protons. c. the interactions between neutrons and electrons neutralize the repulsive forces among the protons. d. the force of the protons repelling each other is small compared to the attraction of the neutrons to each other.