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
Maximum damage to Napoleon&;s army during his amrch to Moscow was done by? 
Select and explain. 
A. Typhus, B. Plague, C. Diarrhea, D. Typhoid
A: Typhus
Answer: A: Typhus 
Explanation: Typhus had been present in Poland and Russia for many years during 18th century. Typhus is caused by Rickettsia prowazekii.