International regimes may be formed in every field of subjects of international relations starting from security issues to environmental issues, and might comprise all international regulations and common standards, such as regimes related to seas, outer spaces, straits and rivers and other waterways as well as economic, financial and commercial subjects or even about diplomatic behaviors. For example, regime of straits, regime of rivers and waterways, international trade regime, international payment regime and international environmental regime exist and are often used to explain the rules governing those areas.

In fact, the concept of regime would cause the question of the limits of state sovereignty. Because states in many subjects would face some limitations of international regimes which constrain their sovereign rights, they are blurred to determine the subjects either domestic or global in character. For example, use of waters, use of natural resources, protection of wild life, animal rights, prevention of environmental pollution are the subjects that states are not willing to share their authority. The correct answer is D.