The correct answer is C) the United States.
Hitler did not expect the United States to enter the war.
Hitler was not considering that the United States entered the war. He was aware of the neutral foreign policy of the United States since the end of World War 1. But what happened was the surprise attack of Japan on Pearl Harbor, the naval U.S. base in Hawaii. That is how he kept his promise to Japan that Germany would engage in war with the United States. Furthermore, Hitler did not like Franklin Roosevelt because the American President always had despicable words for the Nazi ideology.