(A) ** Assassination
(B) Militarism
(C) Nationalism
(D) Imperialism
EXPLANATIONS BELOW
Concept note-1: -The assassination of Archduke Franz Ferdinand was the immediate cause of a war between two great powers-Russia and the Habsburg Austro-Hungarian Empire.
Concept note-2: -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-3: -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.