Which of the following was the main reason that constantinople was a good location

Constantinople was located in a trade crossroad that connected Europe and Asia. Plus, the Bosporus (strait) proportioned a good out to the sea, and the mountains that surrounded the city created a natural protection.

Explanation:

As the Eastern Roman Empire capital, Constantinople was located in a strategical location, that proportioned a good connection to the oriental markets (China and India). The rocky peninsular (the Bosporus) turned the city able to be attacked only by sea, which led the governors to rise walls.