Concept:The Commonwealth of Nations has clearly defined organs; identify the option that belongs to another international body.
Explanation:The Commonwealth Secretariat and the Commonwealth Fund for Technical Cooperation are recognised organs of the Commonwealth.
The Conference of Prime Ministers is the earlier name for the Commonwealth Heads of Government Meeting, so it is also a Commonwealth organ.
However, the Assembly of Heads of State and Government is the main organ of the African Union, not the Commonwealth of Nations.
Therefore, it does not belong to the Commonwealth.
Answer:A. Assembly of Heads of State and Government.