Examine the evidence--a thesis should be written after looking at the evidence and determining how an argument can be constructed using the evidence provided.
A thesis should contain an answer to the question or prompt and then 2-3 reasons why (these are the claims of the thesis). The thesis is then supported or proven with evidence.
senators wanted to make changes to this part of the charter of the League of Nations. President Wilson didn't want this to occur. as a result, we not only didn't join the League of Nations, we didn't ratify the Versailles Treaty. We ended up signing separate peace treaties with the Central Powers
The answer is all of the above