Answer: a. primarily based on trade
Step-by-step explanation:
The Ming Dynasty preceded over one of three of China's golden ages. Such was the peace and prosperity that they brought to China. There was more peace, more food from agriculture and so population increased.
Under the Ming, the economy became primarily based on trade with both domestic and international trade increasing to the point that merchants began to gain power at the expense of the imperial government. The currency used was paper money and silver which were used at alternating times.