The correct answer is The Austrian heir to the throne was assassinated by a Serbian nationalist.
The "spark" moment that helped immediately start World War I was the assassination of Archduke Franz Ferdinand by Serbian nationalist Gavilo Princip. This assassination took place on June 28, 1914. This would help to start a 5 year war that had millions of casualties.
Egyptian nationalization of the Suez Canal during the Suez Crisis meant that "The Egyptian government took control of the canal" specifically from Great Britain.
