Question

what event led to the start of the korean war?
the soviet union invaded south korea.
the united nations forces landed at the bay of inchon.
the south korean army crossed the yalu river.
the north korean army crossed the 38th parallel.

Explanation:

The Korean War began when the North Korean army crossed the 38th parallel, which divided North and South Korea. The Soviet Union did not invade South Korea directly. The UN forces landing at the Bay of Inchon was a later - stage event in the war. The South Korean army did not cross the Yalu River.

Answer:

The North Korean army crossed the 38th parallel.