Why Was It Inevitable That the United States and the Soviet

Why was it inevitable that the United States and the Soviet Union would eventually come into conflict after the war ended?

A) FDR had privately told his advisers that the wartime friendly relationship between both nations could never last.
B) Historically, both nations had never shared long-term interests or values.
C) It was clear as early as the Tehran conference that Stalin had never intended to follow through on any of the Grand Alliance agreements.
D) Exploitation of Iran's northern oil fields suggested the Soviet Union was already ahead of the United States in postwar economic development.
E) The Soviet Union had not fulfilled its obligations from the Yalta conference.