(A) ** League of Nations
(B) Treaty of Versailles
(C) United Nations
(D) Justice League
EXPLANATIONS BELOW
Concept note-1: -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-2: -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-3: -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-4: -The League lasted for 26 years; the United Nations (UN) replaced it in 1946 and inherited several agencies and organisations founded by the League.
Concept note-5: -Unfortunately, the League failed miserably in its intended goal: to prevent another world war from happening (WW2 broke out only two decades later). The idea was for the League of Nations to prevent wars through disarmament, collective security, and negotiation.