Which of the following was the immediate cause of World War I?
a. The launching of the American Navy into the Pacific Ocean
b. The invasion of France by Great Britain
c. The assassination of Archduke Ferdinand
d. The sneak attack by Russia into Germany
Although the overall causes of World War I are complicated, it was "c. The assassination of Archduke Ferdinand" that was the main trigger, since this set in motion a series of alliances.
