Why did the conflict in Korea escalate?

ANorth Korea invaded South Korea.
BThe U.N. became involved in the conflict in an attempt to stop war.
CThe United States sent in troops and medical units to support South Korea.
DIt escalated for all of the above reasons.

Verified Answer :

It escalated when North Korea Invaded South Korea, When the UN became involved in the conflict to stop war, and also when the US sent in troops and medical units to support South Korea.

So, D

The answer is b.The U.N. became involved in the conflict in an attempt to stop war. Hope it help