Answer: d. Bubonic plague
The Black Death (also the Great Plague) was a devastating pandemic that affected Europe from 1347 to 1351. It resulted in the deaths to between 75 to 200 million people in Eurasia. The disease was caused by the bacterium Yersinia pestis, which was carried by Oriental rat fleas. The bubonic plague is thought to have originated in Central Asia. The plague recurred as outbreaks in Europe until the 19th century.