The correct answer is "The Bubonic Plague in the 1300s led to long-term population decline in Europe."
The "Black Death" was the term used to refer to the second Bubonic Plague Pandemic which occurred in Europe over the 14th century. It is believed that the plague originated in Central Asia (The Mongol Empire) and spread from Italy to the rest of Europe. It is estimated that one-third of the population in Europe died as a result of the disease.