At the Yalta Conference, the United States Was Eager to Have

At the Yalta Conference, the United States was eager to have the Soviet Union participate in the projected invasion of Japan because it believed that

A) turning Soviet attention to East Asia would prevent their expansion in central Europe.
B) without Soviet help, the Japanese could not be defeated.
C) Soviet assistance could reduce the number of American casualties.
D) Soviet Siberia would be an ideal base for launching the invasion.
E) the Soviets could help control the Chinese Communists.