Slavery for sure. I believe the second one is economic differences between the North and the South.
Feudalism worked easy because it was a system that worked from top to bottom. At the top you had the King which provided money for the Nobility that provided troops and protection for the king. Then the Nobility would bestow the land to his knights that would give the land to the peasants and they owned the land and farmer on it. The knights would provide military service for food that they farmed.
Once there was a story all bout' how cronos life got twisted upside down but id like to wait a minute and sit right here a tell you how the lightning thief came to be
I believe its c. hope this helps...
