After the division, North Korea attempted to overthrow South Korea's government. When this proved impossible, the North Korean communists began to prepare themselves for war while pretending to negotiate peacefully.

On June 25, 1950, the north began its invasion of the south. The south was taken by surprise, but the armies of South Korea fought bravely to defend their liberties. This action moved the United Nations Security Council to declare the invasion by the north illegal and a threat to peace. A decision was made to help the south, and a UN army, led by the United States, Britain, and France, joined the South Korean forces in an effort to repel the invasion.

Which excerpt from this passage indicates bias?

“The armies of South Korea fought bravely to defend their liberties.”
“On June 25, 1950, the north began its invasion of the south.”
“This action moved the United Nations Security Council to declare the invasion . . . illegal.”
“A UN army . . . joined the South Korean forces in an effort to repel the invasion.”