Answer:
A. Yersinia Pestis
Step-by-step explanation:
Yersinia Pestis is a bacterium which is anaerobic and can infect humans.
The Bubonic plague is caused by a bacterium (Yersinia Pestis). After coming into contact with the bacterium, symptoms begin to present themselves within one to seven days. These symptoms are typically flu-like (fevers, headaches and vomiting). In addition, swelling might occur at the lymph nodes closest to the area where the bacteria entered the skin.
The Pneumonic plague is also caused by the Yersinia Pestis bacterium and presents itself as a severe lung infection. Similar to the Bubonic plague, the symptoms can take between one and seven days to start showing (fevers, headaches, coughing, shortness of breath).