Final answer:
Istanbul, Turkey's largest city, is considered part of both Europe and Asia.
Step-by-step explanation:
D. It is considered part of Europe and Asia
Istanbul, Turkey's largest city, is located on the Bosporus strait, which connects the Black Sea with the Mediterranean Sea. Geographically, Istanbul is situated on both the European and Asian continents, with its western side being in Europe and its eastern side in Asia. This unique location makes Istanbul the only city in the world that spans two continents.