Which Statement About the Korean Conflict Is Correct

Which statement about the Korean conflict is correct?

A) The United Nations authorized the use of force to repel the North Koreans.
B) Chinese troops threatened to enter the conflict, but never did.
C) General MacArthur argued against an invasion of China and for the use of nuclear weapons.
D) Truman removed General Eisenhower from command when he criticized Truman.
E) The war ended with a formal peace treaty.