(A) Militarism
(B) Alliances
(C) Nationalism
(D) ** The assassination of Archduke Francis Ferdinand
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: -The assassination set off a rapid chain of events, as Austria-Hungary immediately blamed the Serbian government for the attack. As large and powerful Russia supported Serbia, Austria asked for assurances that Germany would step in on its side against Russia and its allies, including France and possibly Great Britain.
Concept note-3: -The war started mainly because of four aspects: Militarism, Alliances, Imperialism and Nationalism. This is because big armies become potential threats to other countries, other countries started forcing alliances in order to secure land.