B. To appease something is to try and make better or to subordinate, the opposite of appease is to provoke, or instigate.
The correct answer is: B. land around the river was fertile and capable of supporting farming.
Flood plains often have incredibly rich soil and the "Fertile Crescent" is a classic example of the benefits of flood plains leading towards bountiful farming.
The reason that slave owners prevented enslaved people from gathering in a large group includes that they were aware that if slaves banded together, they might fight for their freedom and assassinate the slave-owners. similar to a slave uprising. They prevented them from teaching them how to write and read as well.
