out of both given theories, which is correct

1.Bubonic Plague Theory - This theory suggests that the Black Death was caused by the bacteria Yersinia pestis. It is believed that fleas that infested rats carried the bacteria, which spread to humans through flea bites.

2.Pneumonic Plague Theory - This theory argues that the Black Death was caused by a more virulent form of the bacteria Yersinia pestis, which could be transmitted directly from person to person through airborne droplets. This form of the disease was much more deadly and spread rapidly, especially in crowded cities.

Both theories are correct as they describe different forms of the same disease. The Bubonic Plague Theory describes the most common form of the disease, which is transmitted through flea bites from infected rats. The Pneumonic Plague Theory describes a more rare, but more deadly form of the disease, which is transmitted through airborne droplets from infected individuals.