Regime theory is a theory for explaining and understanding the international cooperation intending the coordination and harmonization of interest among nations. In fact, international cooperation which means mutual harmonization of policies benefitting to all sides are widely seen in world politics. On the other hand, states in fact would hesitate to form regime in the field of their sovereignty, because regime would limit the sovereign rights of states in those areas in favor of international inspection and sharing their powers with other states. In particular, states would not be willing to share their power about legitimate use of power for internal issues. So they don’t prefer to establish common regimes in these domestic issues if they do not perceive a real threat to their rights inside the country. The correct answer is C.