Which factor that contributed to the fall of the byzantine empire is the author describing in this passage?
during that time it seemed no easy thing to see any man in the streets of byzantium, but all who had the good fortune to be in health were sitting in their houses, either attending the sick or mourning the dead. and if one did succeed in meeting a man going out, he was carrying one of the dead. and work of every description ceased, and all the trades were abandoned by the artisans, and all other work as well, such as each had in hand.
a. invasion of ottoman turks
b. impact of the plague on population
c. attacks by muslim empires
d. effects of justinian code