Read the excerpt from chapter 8 of The Travels of Marco Polo. Many marketable commodities are produced here. And many ships come here laden with cloth of gold and various silken fabrics, and much else besides that I will not attempt to specify, and exchange them for local products. They arrive and depart with full cargoes and the merchants make a handsome profit on the transaction.

Why does the author include information about trade in this text?

to convince readers to visit the region to buy products
to illustrate the wealth and commercial success of the region
to describe why he wants to live in the region
to encourage readers