Answer:
Option: D. Castro began developing ties with the USSR, which was America’s major opponent during the Cold War.
Step-by-step explanation:
During the Cold War, the hostility between America and Cuba remain as Cuba allied with Soviet Russia. Cuba's alliance with the Soviet Union was a security threat to the United States. The Soviet Union after World War II maintained a hostile relationship with the United States because of its political views. Both had wanted to remain as a superpower in the world. The nukes in Cuba led to the Cuban Missile Crisis, which was a direct and dangerous encounter between the two supper nation United States and the Soviet Union.