Question

(a) the senate debate over whether to join the league of nations (b) the role of the american expeditionary forces in combat alongside the allies (c) the changes in traditional ideas about united states noninvolvement in europe (d) the strategies pursued by woodrow wilson when negotiating the treaty of versailles

Explanation:

To solve this, we analyze each option in the context of U.S. involvement in WWI and post - war:

Option A

The Senate debate over joining the League of Nations is a post - WWI political event. It is about the U.S. political decision - making after the war, not directly about the U.S. entry into the war or the change in non - involvement ideas that led to entry.

Option B

The role of the American Expeditionary Forces in combat is about the military actions during the war. It does not address the shift in the U.S. stance from non - involvement to involvement in the war.

Option C

The U.S. had a tradition of non - involvement in European affairs (isolationism). The events leading up to and including U.S. entry into WWI represent a change in this traditional idea. This option directly addresses the shift from non - involvement to involvement, which is central to understanding U.S. participation in WWI.

Option D

The strategies in negotiating the Treaty of Versailles are post - war diplomatic actions. They do not relate to the change in the U.S. stance on European involvement that led to the war.

Answer:

C. The changes in traditional ideas about United States noninvolvement in Europe