Help please , Im always second guessing .

D. Avoid involvement in problems in Europe

Explanation:

Although the League of Nations was created through the Treaty of Versailles, the United States did not join in order to avoid joining another major conflict. The American populace and senators were against any intervention in foreign conflicts. USA should only focus on their economics, this is shown during WW2 that America had only joined the war due to the Japanese Attack on Pearl Harbor. They had no interest to join before that and it was already in the midst of WW2.

battle of saint-mihiel, (12–16 september 1918), allied victory and the first u.s.-led offensive in world war i. the allied attack against the saint-mihiel salient provided the americans with an opportunity to use their forces on the western front en masse.

explanation:

c]extended voting rights to african americans