(A) Militarism
(B) Alliances
(C) ** Nationalism
(D) Imperialism
EXPLANATIONS BELOW
Concept note-1: -Nationalism was a prominent force in early 20th century Europe and a significant cause of World War I. Nationalism is an intense form of patriotism or loyalty to one’s country. Nationalists exaggerate the importance or virtues of their home country, placing its interests above those of other nations.
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: -The spark that ignited World War I was struck in Sarajevo, Bosnia, where Archduke Franz Ferdinand-heir to the Austro-Hungarian Empire-was shot to death along with his wife, Sophie, by the Serbian nationalist Gavrilo Princip on June 28, 1914.
Concept note-4: -It was Serbian nationalism that was the immediate cause of World War I. A Serb Nationalist, Gavrilo Princip, assassinated Archduke Ferdinand of the Austro-Hungarian Empire. This led to the Austro-Hungarian Empire declaring war on Serbia, and Russia reciprocated since it was an ally of Serbia.
Concept note-5: -The idea of ‘aggressive nationalism’ is responsible for the commencement of World War I. It began with the development of this feeling among the Slavic people, who wanted to establish a Greater Serbia solely for the Slavic people. For this purpose, they had to remove Austria-Hungary from the Balkans.