Explanation:

- The United Nations Commission on Sustainable Development (CSD) was initiated following the 1992 Earth Summit.

- This summit, also known as the United Nations Conference on Environment and Development (UNCED), took place in Rio de Janeiro.

- The CSD was established by the United Nations General Assembly in December 1992.

- It was created to ensure effective follow-up of the Earth Summit.

- The commission played a crucial role in monitoring and reporting on implementation of the Earth Summit agreements at local, national, regional, and international levels.

Correct Answer:

- Option 4: 1992