Which important document outlines a plan for sustainable development as a result of the 1992 UN Conference?

The correct answer is Agenda 21, which is a comprehensive plan of action that was adopted by more than 178 countries at the 1992 United Nations Conference on Environment and Development (UNCED), also known as the Earth Summit. This document addresses various aspects of sustainable development, outlining strategies to enhance economic growth while simultaneously promoting environmental protection and social equity.

Agenda 21 emphasizes the necessity of local, national, and global efforts to meet the challenges posed by population growth, resource depletion, and environmental degradation. It serves as a framework for implementing sustainable practices worldwide and promotes public participation as a vital element for effective decision-making and policy implementation.

In contrast, the other options represent different agreements or declarations that focus on different aspects of global governance and human rights. The Rio Declaration includes principles guiding the sustainable development framework, but it is not as comprehensive or actionable as Agenda 21. The Kyoto Protocol is specifically concerned with climate change and emissions reductions, while the Universal Declaration of Human Rights addresses fundamental human rights but does not directly pertain to sustainable development planning. Thus, Agenda 21 stands out as the key document related explicitly to sustainable development from the 1992 UN Conference.