B. The United States proved that communism was a threat around the world.
Explanation:
The Korean War took place between 1950 and 1953. Its components were the Republic of Korea (or South Korea), supported by the armed forces of several countries commanded by the United States; and the Democratic People's Republic of Korea (or North Korea), supported by the People's Republic of China and the Soviet Union. The war was one of the earliest episodes of the Cold War. Excluding more than 3 million civilians and almost 15% of the population of the dead North, it constitutes one of the most bloodthirsty wars in history.
Five years before, after the end of World War II, the United States and the Soviet Union agreed to split Korea into two. They drew the border on the 38th parallel, leaving the North in charge of the Soviet Union and the South in charge of the United States. Each superpower controlled in its respective area the constitution of two new states that were under their respective orbits: the Democratic People's Republic of Korea in the north and the Republic of Korea in the south.
