How did Dwight Eisenhower contribute to the Allied victory to World War II?

A. He was the president of the United States and signed the Lend-Lease Act.
B. He was the political who negotiated a U.S alliance with France and Great Britain.
C. He was the diplomat charged with representing U.S. interests the Yalta Conference.
D. He was the supreme Allied commander and oversaw Operation Overlord.