(A) Militarism
(B) Alliances
(C) Imperialism
(D) ** Nationalism
EXPLANATIONS BELOW
Concept note-1: -A feeling of pride in one’s country is called nationalism. Nationalism also describes the idea that each distinct nationality(a group of people who speak the same language and share the same customs) is entitled to its own government and homeland. Both types of nationalism contributed to the outbreak of WW1.
Concept note-2: -Nationalism led to this situation because it was responsible for pushing countries to expand their influence in Europe. This caused tensions between the major powers of Europe. For example, there was an intense arms race and naval race between several European nations in the buildup to World War I.
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.