Why Did the United Nations Security Council Authorize Its Response

Why did the United Nations Security Council authorize its response to the Korean War?

A) The Soviet Union condemned the attack and took the lead in proposing the resolution.
B) The United States and the Soviet Union cooperated in the wake of the end of the Cold War to end aggressive actions by China.
C) The Soviet Union had been boycotting the Security Council meetings and missed the vote.
D) The Security Council members unanimously agreed that the attack violated international law and had to be condemned.