80 POINTS This is a picture of Joseph Stalin, Franklin Roosevelt, and Winston Churchill at the Tehran Conference in 1943. They were the leaders of the Soviet Union, the United States, and the United Kingdom. During World War II, these men were known as the "Big Three" because they led
A.
the most powerful of the Allied countries.
B.
countries that had declared war on each other.
C.
the countries that suffered the most casualties in the war.
D.
the only countries fighting against Nazi Germany.