Why do protons stay together in the nucleus rather than repel each other?

Electrons in surrounding atoms cancel the repulsive forces between protons.
Nuclear forces overcome electrostatic forces between protons in the nucleus.
Electrostatic forces between protons and neutrons hold the nucleus together.
Neutrons surround protons and keep them far enough apart to prevent repuision.

The correct answer is: Nuclear forces overcome electrostatic forces between protons in the nucleus.