Which of the Following Appears to Have Led to the Cold

Which of the following appears to have led to the cold war in retrospect?

A) Truman's refusal to adopt an antagonistic foreign policy and his ongoing efforts at collaboration with the Soviet Union
B) ideological competition between democratic capitalism and totalitarian communism and their opposing views of what the postwar world should become
C) the ongoing threat of Nazism following the Second World War around the globe, but most especially in the United States and the Soviet Union
D) the lack of Russian casualties and invasions in Russia during the Second World War that left the nation more powerful than ever before
E) the upholding of promises made at the Yalta Conference following the Second World War by all parties involved and the independence of Eastern European nations