The correct answer is D. Before United States' involvement in World War I, American citizens wanted to stay neutral until innocent Americans were killed.
Explanation:
The United States decided to put aside its neutral position and enter the First World War for various reasons. Until that moment the United States had maintained its position outside the conflict under the command of Woodrow Wilson, who had avoided all the participation of the country, guided by his convictions, and resisting a strong internal opposition.
Wilson decided to remain outside even after the sinking of the Lusitania, but this would be the first of a series of events that would end up putting the United States along with the allies, just a few months after Wilson's re-election.
The German policy of attacking non-military ships with submarines had the most dramatic episode in May 1915, when a German submarine fired torpedoes without any warning at RMS Lusitania, a British ship dedicated to passenger transport.
As a result of the attack, which took place off the coast of Ireland, 1198 people died, many of them Americans (the ship was on the New York-Liverpool route). The public protests in the United States were very strong; the Germans decided to stop attacks of this type in 1916.
In spite of the strong rejection that that policy of German war had caused, in 1917 Berlin publicly announced that the attacks would continue but this time they would focus on merchant ships.
Behind this policy was the belief that Britain would capitulate if it managed to isolate it from the supplies that came to it from the United States. This decision would lead to the rupture of diplomatic relations between both nations on February 3.
The sinking was never forgotten and weighed in the minds of the Americans when, two years later, they decided to support the entry into the war.
The economic interests of the United States with the allied countries, especially Great Britain and France, weighed in the decision to enter into conflict. Until then, commercial ties had been maintained, since Britain had control of the seas and prevented ships from entering Germany. But once the attacks with submarines began to take place, the economic losses were incalculable, as well as the losses in human lives.
These, added to the deep indignation of the American people in front of the supposed cruel behaviors on the part of the German army, predisposed the population to support the armed confrontation.
