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.
Puritans was a religion which was formed as a movement which had the motto to reform the church in 15th century but not to be separated from them. Irquois is a type of religion which believes that the religion is from the nature and we have to respect to it because we draw everything which is required from the nature only.
Puritans believe that everything which happens is done by the God where as Irquois believe that everything is natural and done by nature. Puritans believe that everything is predetermined before a person's birth where as Irquois believe that it is an entity which governs the life of a person is.
B. An authoritarian populist
I think it is D
Hope my answer help?