A. Former republics are more difficult to rule than hereditary states, and they will rebel if they are not tightly controlled
Explanation:
The option that best state the main idea of the passage is Option A: Former republics are more difficult to rule than hereditary states, and they will rebel if they are not tightly controlled.
The excerpt tends to make a comparison between between hereditary states and former republics. It reveals the difference between the two.
The excerpt shows how easy it is to rule hereditary states while also revealing the difficulty any prince may encounter in former republics. The former republics have greater desire and more desire for vegeance. They need to be tightly controlled.
I'm sure there were some differences but no matter what slaves were treated like property and work forces. They were used to complete a task in both the US and South America, they were treated poorly as well.