Answer:
b. A reliable food production and distribution system
Step-by-step explanation:
The Tang and Song Empires were successful at creating increased food production. Irrigation systems were responsible for more growing areas and particularly helped produced more rice. The empires also manipulated the landscape to create more land to farm. Terrace systems within the land also increased the amount of land that could be farmed at any one time. Cotton, tea, and rice became the most produced crops making money for the empires.