The answer is the last one , D
Answer:
The answer would be nationalism.
Explanation:
They have different ecomimic values due to their differences in place and times. As well as being different nationalites, they are going to be different socially too. Considering they may have different languages, it would affect the way people from the north would socialize to people in the south. The USA and China have different political reasons and presidents so of course this would be the same wiht the North and South.
It was the Truman Doctrine.
The Iron Curtain was the metaphorical barrier that seemed to split the Eastern Bloc from Western Europe. It was first mentioned by Churchill. The Berlin Wall was the physical embodiment of this "Curtain" that was constructed by the USSR to prevent Eastern Europeans from migrating. The Marshall Plan sent $13 billion to European nations to help them rebuild after WWII. The Truman Doctrine was specifically put in place to contain communism by aiding nations that were "at risk" so they would not turn to communism to solve their problems.
C the end of Reconstruction
