Which statement about World War II is correct?
Choose all correct answers.

A. The Japanese developed long-range rockets, called V-2s, to launch against the United States.
B. Stalin refused to accept aid from the United States because it was not a communist country.
C. To defend its territories in Asia and South America, Italy had to fight a two-ocean war.
D. German submarines, called U-boats, sank many Allied ships in the Atlantic Ocean.