This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
[{'content': 'Maximum damage to Napoleon&;s army during his amrch to Moscow was done by? \nSelect and explain. \nA. Typhus, B. Plague, C. Diarrhea, D. Typhoid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Typhus had been present in Poland and Russia for many years during 18th century. Typhus is caused by Rickettsia prowazekii.', 'role': 'assistant'}]