Describe the popular trade items inside the Indian subcontinent.

Rice, wheat, barley, and millet was able to sustain India itself. Many of the specialized crops could only grow in specific regions of India such as spices.

What bodies of water were used to exchange trade items. What were some of the key trade routes?

The largest body of water used for trade was the Indian Ocean and a key trade route involved the Arabian Sea and the Bay of Bengal

What special commodities were produced for the commercial market? 

The most special commodities were the high quality cotton textiles.