(A) ** It had an isolationist policy which meant that it did not want to get involved in foreign wars
(B) The US has too much debt due the the Great Depression and enough problems to solve on its own
(C) The US disagreed with keeping the Germans from joining
(D) The US disagreed with keeping the Soviet Union from joining.
EXPLANATIONS BELOW
Concept note-1: -The League of Nations was established at the end of World War I as an international peacekeeping organization. Although US President Woodrow Wilson was an enthusiastic proponent of the League, the United States did not officially join the League of Nations due to opposition from isolationists in Congress.
Concept note-2: -Congress did not ratify the treaty, and the United States refused to take part in the League of Nations. Isolationists in Congress feared it would draw the United Sates into international affairs unnecessarily.
Concept note-3: -Isolationists believed that World War II was ultimately a dispute between foreign nations and that the United States had no good reason to get involved. The best policy, they claimed, was for the United States to build up its own defenses and avoid antagonizing either side.
Concept note-4: -World War II (1939 to 1945) While avoiding the conflict until 1941, World War II marked a turning point for American isolationism.