The correct answer is A) Cuba.
The nation in the Western hemisphere, "right on America's doorstep," that became pro-Communist in 1969 was Cuba.
Under the heavy influenced and support of the Soviet Union, Fidel Castro won the Revolution of Cuba and installed a Communist form of government on the island of Cuba in 1959. It represented a great risk for the United States. Being so close to the Florida Peninsula, Cuba was now under a Communist regime supported by the USSR. During those years of the Cold War, Cuba played a major role in the conflict between the Soviet Union and the United States, basically with the Cuban Missiles Crises that set the world on the brink of another World War.
