Question

what military advancement contributed most to the ottoman empires successful conquest of constantinople in 1453?
the use of large gunpowder cannons to destroy the citys walls
a naval blockade of the citys harbor
traditional cavalry charges against the city gates
a surprise alliance with european christian forces

Explanation:

The Ottoman Empire used large gunpowder cannons, like Orban's cannon, which were powerful enough to breach Constantinople's thick walls. Naval blockade (B) limited supplies but wasn't decisive. Cavalry charges (C) couldn't overcome wall - based defenses. The Ottomans were in conflict with European Christian forces (D), not in alliance.

Answer:

The use of large gunpowder cannons to destroy the city’s walls.