This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Which of the following causes epidemic typhus \nSelect and explain. \nA. R. typhi, B. R. prowazekii, C. R. rickettsii, D. R. tsutsugamushi', 'role': 'user'}, {'content': "Answer: B \nExplanation: R prawazekii causes epidemic typhus,distribution is worldwide, in recent times main foci have been eastern Europe,Africa,South America and Asia.in india the endemic spot is kashmir,Humans are the only natural veebrate host,pediculus humanus corporis(human body louse) is the vector,so this disease is also called loseborne typhus Ref:Ananthnarayan and paniker's microbiology 10th edition", 'role': 'assistant'}]