Why Might Nuclear Proliferation Cause Peace

Why might nuclear proliferation cause peace?

A) There is a strong norm against starting a nuclear war.
B) Large-scale nuclear proliferation will cause countries to create a new international organization that will regulate nuclear weapons.
C) Countries with nuclear weapons will have no reason to go to war with other countries.
D) Nuclear powers such as the United States can threaten to punish states that start wars.
E) Possessing nuclear weapons increases the costs of war.