(A) Nationalism
(B) Militarism
(C) Imperialism
(D) Assassination of Archduke Franz Ferdinand
(E) ** All of the Above
EXPLANATIONS BELOW
Concept note-1: -The main causes of World War 1 were alliances between countries, militarism, nationalism, imperialism, secret diplomacy, and internationalism. The assassination of Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, by Gavrilo Princip in Bosnia is widely accepted as the starting point for World War I.
Concept note-2: -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. In June 1914, a Serbian-nationalist terrorist group called the Black Hand sent groups to assassinate the Archduke.
Concept note-3: -Causes of World War I. It is widely believed that the assassination of Archduke Franz Ferdinand and his wife during a visit to Serbia is the spark that ignited the conflict of World War I.
Concept note-4: -The main causes of WWI were nationalism, imperialism, militarism, and the system of alliances.