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A. Why was the monsoon season so important to farmers in the Indian River Basin?

The season was so important because it provided excess water they could use to grow crops. Without this water, agriculture lacked productivity.

B. Describe the irrigation systems that were used in the basin.

Systems that were used in the basin were canals, wells, tunnels, dams, and reservoirs. Although, there were many river less areas in India.

C. Why was India’s population able to grow throughout the postclassical era?

India's population grew throughout the postclassical era because there was increased productivity like agriculture and trade.