The births and immigrants are equal to deaths and out going migrants.
I believe the answer is: C. He was worried about his border with North Korea being in jeopardy.
Mao zedong feared that if he let the allied forces took control of north korea, the allied forces would be able to establish a navy base on that territory and exposed the chinese mainland from naval attack from north Korea. Because of this, he decided to help the north korean with both millitary soldiers and supplies.
