North Korea has a closer relationship with China because both of those countries have, at some point in their history, implemented a communist regime. Also, during the Korean war, the United States were very involved which could cause a feeling of animosity between the U.S. and North Korea.
In the 1860s, most factories were located in the North of the United States, mostly because the South was largely agricultural and remained this way for many years.
The last one and I'm pretty sure the second one
B. They were written to be codes of laws for early civilizations.