(A) Militarism
(B) Alliances
(C) Imperialism
(D) ** Nationalism
EXPLANATIONS BELOW
Concept note-1: -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-2: -There is no doubt that the four M.A.I.N. longterm causes of WW1, namely Militarism, Alliances, Imperialism and Nationalism, all played their part in the road to war; as did the infamous spark of Archduke Franz Ferdinand’s assassination, and even the Blank Cheque and the Schlieffen Plan, as mentioned above.