The correct response is:
A
The United States did not want to get involved in European conflicts.
Despite President Wilson's advocacy for the League of Nations as a means to promote peace and prevent future wars, there was significant opposition within the U.S. Senate. Many senators were concerned that joining the League would entangle the United States in international conflicts and compromise its sovereignty. Ultimately, the Senate did not ratify the Treaty of Versailles, which included the League of Nations, and therefore the U.S. did not join.