Why was the death of darius important to alexander's conquest of persia(dbq alexander the great)

The correct answer is D. The Crusades contributed to the end of the Middle Ages by undermining the authority of European monarchies.

Changes in society and culture as a consequence of the Crusades reached the fourteenth century. The most important was the reduction of the power of the European kings, as a consequence of great peasant rebellions and also because these kings strove to control an undisciplined nobility. A technical advance that contributed to weakening the european kingdoms was the introduction of firearms, because with it it was possible to destroy the armor and the strengths of the warriors, who until then were invincible.