The correct answer is D. The Cold War. The United States and the Soviet Union engaged in a prolonged period of tension and rivalry after World War II, which became known as the Cold War. It was a primarily ideological conflict between the two superpowers, with the United States championing capitalism and democracy, and the Soviet Union promoting communism. This conflict lasted from the late 1940s until the early 1990s and involved political, economic, and military competition between the two nations without direct military confrontation.
