d) RMS Lusitania

The sinking of the RMS Lusitania by a German U-boat in 1915 marked a pivotal moment in World War I. The British ocean liner was en route from New York to Liverpool when it was struck off the coast of Ireland, resulting in the death of 1,198 passengers, including 128 Americans. This event significantly escalated tensions between the United States and Germany. The tragedy of the Lusitania was instrumental in shifting public opinion in the U.S. against Germany, paving the way for America’s eventual entry into the war in 1917.