Final answer:
The Hagia Sophia was originally a B. cathedral, indicated by its traditional basilica style ground plan, and was later converted into a mosque by Sultan Mehmed II in 1453 after the conquest of Constantinople.
Step-by-step explanation:
The ground plan of the Hagia Sophia suggests that it was a cathedral. The layout of the building, which follows the traditional basilica style with a rectangular shape leading to an apse, indicates its original use as a place of Christian worship. The Hagia Sophia was an architectural marvel of its time, commissioned by Emperor Justinian, boasting a grand central dome and embellishments made with marble from various parts of the ancient world.
In 1453, after Constantinople was conquered by the Muslim Turks, Sultan Mehmed II converted the cathedral into a mosque, which included adding minarets and Arabic iconography. Over time, the structure has also served as a museum and is currently a mosque again. Its historical transformations and architectural features highlight its significance to both the Christian and Muslim communities over several centuries.