The correct answer is letter C. The assassination of Archduke Francis Ferdinand. That is the event that triggered the start of World War I. Archduke Ferdinand was from Austria, the heir to the throne of Austria-Hungary. He was assassinated by Yugoslav nationalist Gavrilo Princip on June 1914.
The event that triggered the start of World War I was the fact that Archduke Francis Ferdinand was assassinated during his tour on the Balkans - c.
Archduke Francis Ferdinand was a very important figure viewed from a historical perspective and with him being assassinated, everybody knew that dire consequences would happen after this.
