The korean war (1950–1953) marked the first time that
a. the united nations used military force to oppose aggression.
b. american and asian forces fought against each other.
c. a major disagreement between arose between the soviet union and the united states.
d. an atomic bomb was used in warfare.

The correct answer is - c. a major disagreement arose between the Soviet Union and the United States.

The Korean War was a war where there was a major disagreement between the two biggest forces on the global scene, the Soviet Union and the United States. This was due to the different interests that both sides had, and what had they planned for the Korean Peninsula. Both of them wanted to strengthen their positions in East Asia and this was a great opportunity for both of them. So in general, the war was heavily sponsored by the Soviets, sponsoring North Korea, and the Americans, sponsoring South Korea, and the end result was a divided nation with lots of bad blood between the two newly formed countries, and the biggest sufferers were the ordinary people.