Answer:
Puerto Rico, Guam and the Philippines
Explanation:
I think its D: The Red Sea
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 answer to your question is D.