Answer:
a. China's isolationism policy
Step-by-step explanation:
During the Ming dynasty, China adopted a policy of isolationism, which meant that they cut themselves off from the rest of the world and limited their trade and diplomatic relations with other countries. This policy was intended to protect China from foreign influence and maintain their cultural and political traditions. However, this policy had negative consequences for the Chinese economy, as it limited their access to new technologies, ideas, and resources that could have helped them to grow and develop. As a result, the Chinese economy stagnated and declined during the Ming dynasty.