(A) the United Nations
(B) ** the League of Nations
(C) the North Atlantic Treaty Organization
(D) the Congress of Vienna
EXPLANATIONS BELOW
Concept note-1: -The predecessor of the United Nations was the League of Nations, established in 1919, after World War I, under the Treaty of Versailles “to promote international cooperation and to achieve peace and security."
Concept note-2: -The League of Nations, 1920. The League of Nations was an international organization, headquartered in Geneva, Switzerland, created after the First World War to provide a forum for resolving international disputes.
Concept note-3: -The League of Nations (French: Société des Nations [sɔsjete de nɑsjɔ̃]) was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace.
Concept note-4: -Overview. The League of Nations was established at the end of World War I as an international peacekeeping organization. Although US President Woodrow Wilson was an enthusiastic proponent of the League, the United States did not officially join the League of Nations due to opposition from isolationists in Congress.
Concept note-5: -However, Wilson’s capstone point calling for a world organization that would provide some system of collective security was incorporated into the Treaty of Versailles. This organization would later be known as the League of Nations.