The Atlantic Charter was signed in 1941 by Franklin D. Roosevelt and Winston Churchill. It defined the allied goals for the structure and division of the post-war world. It was an idealistic document that aimed to ensure no territorial changes against the wishes of the people and the restoration of national self-government to those deprived of it. The Charter held significant influence in the break-up of European colonial ownership following the end of the war. 

The Second World War quickly became a conflict between two large groups of nations joined by treaties. While the U.S. remained a neutral nation in principle until attacked by Japan on December 7, 1941, the Roosevelt Administration was assisting the Allied Nations of Great Britain and France. After declaring war on Japan, the U.S. also declared war on the other Axis Powers of Germany and Italy, while fighting allies like Romania and Bulgaria later in the war. The Soviet Union and the United States became Allies during the War, although the seeds of Cold War antagonism underlined their alliance.

The Yalta Conference was convened by Allied leaders Roosevelt, Churchill, and Stalin, the respective leaders of America, Britain, and the Soviet Union.  These three nations were the leading powers of the Allied forces in World War II.  Adolf Hitler was still leader of Germany in February of 1945, and still fighting the Allies, so all answer choices with Konrad Adenauer should be eliminated.

The Axis Powers were, broadly speaking, America's opponents in World War II, but their exact allies were not always straightforward. Upon entering the war in December of 1941, the United States declared war on Japan, Germany, Italy, Romania, Hungary, and other Allied affiliated states. Those countries possessed by Germany were in a different condition, as the German speaking Austrians and Czechs were largely affilliated with the Nazis. France, however, saw a "Free French" army and shadow government form, which was a determined ally of the United States.

The Potsdam Conference was a meeting that occurred in 1945 among the so-called "Big Three:" Soviet leader Joseph Stalin, British Prime Minister Winston Churchill (replaced on July 26 by Prime Minister Clement Attlee), and U.S. President Harry Truman, in Potsdam, Germany. The three leaders had gathered to discuss how to punish Germany after the war, establish order in Europe, and negotiate treaties.

The Treaty of Versailles, signed in 1919, was a peace treaty that ended the state of war following the devastation of World War I. It made sure Germany accepted all responsibility for damages during the war. The Treaty included provisions stating that Germany had to give back land acquired during the war, that Germany had to pay over 31 billion dollars, and that Germany allowed the countries it had acquired during the war to be sovereign nations included in the League of Nations.

The Good Neighbor Policy, defined by its main principle of non-intervention in the domestic affairs of Latin American nations, was implemented by Franklin Roosevelt's administration in the 1930s. Instead of military intervention in Latin American nations, Roosevelt favored peaceful, reciprocal trade relations with said nations. Both Theodore Roosevelt and Woodrow Wilson had favored military intervention in certain Latin American nations during their presidencies, while Harry Truman and John F. Kennedy were presidents later, during the Cold War, when the US was again starting to take a more interventionist approach in Latin America.

Germany, Austria-Hungary, and Italy were all part of the Triple Alliance. Basically, what that meant, was that all three countries had interloping “aid” treaties; that is, if country X attacks Italy, Germany and Austria-Hungary are going to come help Italy.

Great Britain, France, and Russia were all members of the Triple Entente. This one is slightly easier to remember than the Triple Alliance because the word “entente” is French—clearly, then, the French belong in that group. At any rate, this question is just as important for what it doesn’t ask as for what it does. Note that the question does not ask which countries fought each other in the war; just what countries had overlapping treaties with each other.

The “western front” became a major focal point for WWI (and also was the setting of a novel/memoir by Erich Marie Remarque). WWI was the first time that trench warfare was employed and used so brutally; the western front turned into a “war of attrition,” with either side using gas warfare and tanks to inflict massive injury to the other.