A. The sinking of the Lusitania
B. The assassination of Archduke Franz Ferdinand
C. The invasion of Poland
D. The signing of the Treaty of Versailles
Answer: The assassination of Archduke Franz Ferdinand
Which event sparked the beginning of World War I?
Additional Information: The assassination of Archduke Franz Ferdinand of Austria in 1914 is widely regarded as the immediate catalyst for World War I.
Subjects: World History, General Knowledge