The correct option is B.
Corn was the major diet that was eaten then and the spread of corn led to development in the form of greater urban density and more complex social organisation. Maize cultivation led to the development of irrigation system which also led to building of village and towns.
To inform you about serfs, they were considered the base or main structure of the economic system, due to the fact that they supplied labor, goods, and any other necessities to the entire kingdom.
They were basically slaves, considering that they worked on the lands for their landlords, paid taxes and were responsible for nearly EVERYTHING that was involved with the lords property.
Fun Fact: The most common serf was a villain.
Thank you for asking questions! It helps you and helps me educate myself at the same time.
Joseph Pulitzer is known for being one of the first journalists to use the 'new journalism'. He was also a publisher for the New York World and St. Louis Post Dispatch. He also served as a member of the US House of Representative, from New York's 9th District.
Hope this helps
Cleopatra was involved with caesar