Final answer:
The United States responded to the sinking of the Lusitania by declaring war on Germany and the Central Powers.
Step-by-step explanation:
After the sinking of the Lusitania, the United States responded by declaring war on Germany and the Central Powers. This event, known as the sinking of the Lusitania, was a major factor that pushed the United States into World War I. The attack on a French passenger ship did not directly lead to the United States' declaration of war.
Learn more about United States response to the sinking of the Lusitania