a.I want readers to keep my work and b
I believe the answer is: C. federal system.
In a federal system, the central government granted each states the freedom to govern themselves as long as they do it within the scope of legislature that created by the central government. In this system, the states must bow down to the central regulation if there is any contradiction between states and federal laws.
Answer: 1, 2, and 3.
Explanation:
Re-establishing Chinese rule after the defeat of the Mongols, the Ming dynasty took an isolationist and authoritarian approach to leadership. Thanks to the dynasty's fear of foreign invasion, the Great Wall was significantly lengthened and Beijing's famous Forbidden City built under direction of the Ming.