SAT World History Practice Question

Why did the Korean War ultimately end in a stalemate?

1. A.Because UN forces were unable to penetrate North Korean territory
2. B.Because the South Korean government was not supported by the Korean people
3. C.Because Soviet forces threatened to enter the battle on North Korea's behalf
4. D.Because the Chinese entered the war and forced UN troops to retreat
5. E.Because the North Koreans did not have the resources to take South Korea entirely