Answer:
A. It became a major center of trade.
Step-by-step explanation:
Constantinople's location is a major center of trade because all the goods comes from other countries into Constantinople and them go further to the western countries. They used tolls for anything passing through their rivers and waterways which ultimately enhances the economy. Goods comes from India. Africa, China and other regions were brought into Constantinople and then shipped towards west. It also safer empire because of its geographic location which boost the trade in this region.