Read the following excerpt from Gabrielem de Mussis of Piacenza, Italy, 1349.
“Oh God! See how the heathen Tartar [Mongol] races, pouring together from all sides... besieged the trapped Christians there for almost three years... But behold, the whole army was affected by a disease which overran the Tartars and killed thousands upon thousands every day. It was as though arrows were raining down from heaven to strike and crush the Tartars’ arrogance. All medical advice and attention was useless; the Tartars died as soon as the signs of disease appeared on their bodies: swellings in the armpit or groin caused by coagulating humours, followed by a putrid fever. The dying Tartars... ordered corpses to be placed in catapults and lobbed into the city in the hope that the intolerable stench would kill everyone inside.”
Which historical argument is best supported by this primary source?
A. The Mongols were affected by the bubonic plague prior to Europeans.
B. Fleas were the primary means of spreading the bubonic plague.
C. Trade routes between Asia and Europe spread the bubonic plague.
D. Poor sanitation in cities caused an outbreak of the bubonic plague.