Answer:
A
Explanation:
the answer is A because since Woodrow Wilson ratified the Treaty of Versailles by himself he lost the support of amy republicans back home in the Senate, and this caused the Treaty of Versaille to not be ratified in the United States. And because of that the League of NAtions lost out on a huge power house on the world stage, and because of this the U.S. had no say in European affairs and that left Europe to its own devices and that is what led to the start of WWII.