Use the timeline below to answer the question: Which of the following best completes the flowchart of the events that led up to WWI?
A. Archduke Franz Ferdinand is assassinated
B. European countries try to form alliances with the United States
C. The U.S. joins the war
D. A German U-Boat torpedoed and sank the passenger liner Lusitania
Here is the completed flowchart:
1. Growing tensions in Europe
2. Assassination of Archduke Franz Ferdinand
3. Austria-Hungary declares war on Serbia
4. Germany declares war on Russia
5. Germany declares war on France
6. Great Britain declares war on Germany
7. U-Boat attacks on passenger ships, including the Lusitania
8. The United States enters the war
Therefore, the answer is D. A German U-Boat torpedoed and sank the passenger liner Lusitania.