The correct answer is: The domino theory describes the U.S. policy for stopping the Soviet Union from influencing other countries in which people were staging revolutions and independence movements.
The domino theory suggested that if one country fell to communism, neighboring countries would follow, similar to a line of falling dominos. This led the United States to intervene in various countries during the Cold War to prevent the spread of communism, particularly in regions where independence movements or revolutions were taking place.