How did US General MacArthur's landing in Korea and successful push toward the Chinese border affect the course of the Korean War?
A. As U.S. forces advanced, and winter set in, China supplied North Korean troops with food and ammunition.
B. As MacArthur's troops neared China's border, Mao Zedong asked the UN to help settle the Korean War.
C. Observing MacArthur's success, the Soviet Union and China sent guns and warplanes to aid North Korea.
D. Fearing the American invasion in China, Mao Zedong dispatched troops to support North Korea's armies.