Which best describes the role of Constantinople in the Byzantine Empire?

Constantinople was a main trading center.

Constantinople was a secondary trading center.

Constantinople was a Greek trading center.

Constantinople was a Roman trading center.

Constantinople was a main trading center.

Constantinople sat between Europe and Asia making it geographically perfect to become a trading center.

Constantinople became a city of wealth and the center of Byzantine trade. Due to its prime location, the city was a target of military siege in particular by the Ottoman Empire. Eventually the city was taken by the Ottoman Empire and was changed in name to Istanbul.