Final answer:
The Siege of Caffa is important because it significantly contributed to the spread of the Black Death into Europe, which had devastating demographic effects and led to major societal and economic changes. The correct option is c.
Step-by-step explanation:
The Siege of Caffa is historically significant for several reasons, but most notably because it is believed to have contributed to the spread of the Black Death into Europe.
During the siege by the Mongols, it is reported that they catapulted plague-ridden corpses over the walls into the city in an early form of biological warfare, which helped to transmit the disease to the inhabitants of Caffa. However, the Black Death was most likely spread to Europe primarily through flea-infested rats that traveled on merchant ships.
From Caffa, the plague traveled to Italy in 1347 aboard the ships, leading to the widespread outbreak of the disease across Europe. Consequently, the correct answer to the student's question is c) It led to the spread of the Black Death.
This event not only had devastating demographic effects, resulting in the deaths of millions but also induced significant economic and social changes that eventually led to the undermining of the feudal system and the rise of modern economic systems. The correct option is c.