Final answer:
The IMMEDIATE cause of World War I was the assassination of Archduke Franz Ferdinand of Austria-Hungary, which triggered a series of alliances and mobilizations among European powers. Rivalries and tensions among major European powers also contributed to the start of the war.
Step-by-step explanation:
The IMMEDIATE cause of World War I was the assassination of Archduke Franz Ferdinand of Austria-Hungary. On June 28, 1914, the archduke was assassinated by a Serbian nationalist in Sarajevo. This event triggered a series of alliances and mobilizations among European powers, leading to the outbreak of war.
Another important factor that contributed to the start of the war was the presence of rivalries and tensions among the major European powers, such as Germany, Austria-Hungary, and Britain, which had been growing for years. These tensions were heightened by a mix of political, economic, and territorial disputes.
The spark caused by the assassination and the underlying rivalries ignited a chain reaction of declarations of war, marking the beginning of World War I.
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