Concept:The Economic and Social Council (ECOSOC) is one of the principal organs of the United Nations.
Explanation:ECOSOC coordinates global economic, social, cultural, and humanitarian affairs.
It is a key UN body that addresses issues such as poverty, sustainable development, and social progress.
ECOSOC works under the general authority of the UN General Assembly.
Therefore, it belongs to the United Nations, not to the African Union, Commonwealth of Nations, or NEPAD.
Answer:C. United Nations