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.
in 2015 it was $3.8 trillion so it's at least in the trillions that the federal government spends each year.
Hope this helps
God bless u
- Kayla <3
B. interpret an event to make the politician who hired him or her to look good