The correct answer is D) make the world safe for democracy.
American leaders explained their decisions to enter World War 1 by saying they wanted to make the world safe for democracy.
The United States had expressed its intention to remain neutral and does not participate in European conflicts. But many incidents made government officials and President Wilson change their opinion. The Zimmerman telegram and the Lusitania incident made the United States enter World War on April 6, 1917. The discourse of democracy was one of the arguments that the government used. It said that Germany was a menace to the democracy of the world.
The other options of the question were a) win the war to gain new territory, b) keep the oceans safe for shipping, and c) punish those who made war on civilians.