(A) Militarism
(B) Alliance System
(C) ** Isolationism
(D) Nationalism
EXPLANATIONS BELOW
Concept note-1: -Expert-Verified Answer. Militarism, Alliances and Imperialism are the cause of World War I. liberalism is not the cause of World War I.
Concept note-2: -This increase in militarism helped push the countries involved into war. The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary.
Concept note-3: -They include the impact of the Treaty of Versailles following WWI, the worldwide economic depression, failure of appeasement, the rise of militarism in Germany and Japan, and the failure of the League of Nations.
Concept note-4: -The overall cause of World War was the assassination of Archduke Franz Ferdinand. Nationalism was a great cause of World War one because of countries being greedy and not negotiating. Nationalism shows you are proud of your country and want it to be the best.