Why was it difficult for the Ottomans to capture Constantinople?
A. The city was surrounded by territory controlled by the Byzantine Empire, making it hard for the Ottomans to enter the city.
B. The city was surrounded by water on three sides and heavily protected with stone walls, making it hard to penetrate.
C. The Byzantine Empire had an army that was considerably larger than the Ottoman army, making it difficult to conquer.
D. The Ottomans did not have access to heavy artillery, making it impossible to break through the city's walls.