Answer :
The Black Death had a devastating adverse effect on the rise of the merchant class in medieval society. The black death or the bubonic plague caused a great decline in trade and commerce. Trade had almost stopped as a result of the huge number of deaths and monetary implications arising out of it. This had a great impact on the society.
As a result of the spread of the black death, a very large number of people lost their lives. There were not many people left to look over farm animals and crops. The peasants took advantage of this situation and started charging three times more pay for the same amount of work that they did before the plague. The landowners had to comply with them due to a shortage of workers. As the workers earned their salaries in lesser number of days, they refused to work more leading to utter neglect of crops and farm animals.
The plague spread along the major trading routes of the medieval age through the rodent population. It completely inverted turned the economy. Skilled craftsmen and traders died in huge numbers leaving a huge gap between demand and supply. Thus, the bubonic plague had the most devastating effect on the rise of the merchant class.