The correct answer is D) the United States.
The Cuban Revolution in the 1950s led to the end of the trade relationship between Cuba and the United States.
It was a time in modern history in which revolutionary leader Fidel Castro won the war and became the new ruler of the Island of Cuba. At this very moment, Castro instilled a new form of Government: Communism. Of course, he received the support of the Soviet Union to become the new ruler of Cuba.
This action infuriated the United States and one of the first actions taken was to end the trade relationship with Cuba.
Those were the tense Cold War years in which the United States and the Soviet Union competed in the arms race, the space race, and the spread/containment of Communism around the world.