which of the following were strategies used by Sultan Mehmed 2 (Mehmed the Conquerer) to conquer the Byzantine city of Constantinople? choose all that apply.
A) he plugged the sewers and flooded the city.
B) he ordered his fleet of ships to be carried overland, thus attacking from an unexpected direction
C) he hired a Hungarian engineer to forge the largest cannon in the worlds
D) he used Serbian miners to dig tunnels under the walls of the city