Sometimes the correct answer to historical questions is not unique. So you have to look at the core of the topic. And sometimes you can't just read textbooks, read topics, and read topics over and over again. Although the textbook is the basis of the topic, if the questions raised have a background in the topic, they are mainly based on the topic.

And c, Europe is divided because of a Marshall Plan, different ideologies and the hegemony between the United States and the Soviet Union. Moreover, Marshall plan is not to split Europe, but to control Europe and expand the market through economy.

I hope you understand.