The correct answer is D) supported democratic South Korea against communist-backed North Korea.
The statement that best shows how the US response to the Korean War followed the policy of containment is "supported democratic South Korea against communist-backed North Korea."
During the Cold War years, the Soviet Union tried to spread Communist in many countries of the world. But the United States applied the foreign policy of containment to stop it. The USSR already controlled countries such as East Germany, Czechoslovakia, Rumania, Albany, Poland, Hungary, and Poland. It backed North Korea as well as North Vietnam, years later.
