**Introduction:**
International resources are those resources that are shared or regulated by multiple countries through international agreements or institutions. These resources can be found in various forms such as natural resources, airspace, outer space, and the high seas.

**Explanation:**
The correct statement among the given options is option 'A': Resources which are regulated by international institutions. Here is a detailed explanation of why this statement is correct:

1. **Resources regulated by international institutions**: International resources are often regulated by international institutions or organizations to ensure fair and sustainable use. These institutions establish rules, regulations, and agreements to manage the access, exploitation, and conservation of these resources. Some examples of international institutions that regulate resources include the United Nations, World Trade Organization, and International Maritime Organization.

2. **Territorial waters**: Option 'B' states that international resources are those that lie beyond territorial waters. While it is true that resources beyond territorial waters are often considered part of the international commons, not all international resources are found in this specific location. International resources can be found in various areas, including land, oceans, and outer space.

3. **International frontier**: Option 'C' suggests that international resources are found along the international frontier. While it is possible for some resources to be located along international borders or frontiers, this statement does not encompass the full scope of international resources. International resources can be found in various locations, including areas that are not directly adjacent to international borders.

4. **Not yet developed resources**: Option 'D' states that international resources are those that are not yet developed. However, international resources can include both developed and undeveloped resources. The key aspect that defines an international resource is its shared or regulated nature, rather than its development status.

**Conclusion:**
In conclusion, the correct statement about international resources is that they are resources which are regulated by international institutions. This statement accurately captures the shared and regulated nature of international resources, which can be found in various locations and can include both developed and undeveloped resources.

International resources are those resources which international Institutions regulate the ocean resources beyond 200 nautical miles of the Exclusive Economic Zone belong to open ocean and no individual country can utilize these without the concurrence of international institutions