This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'Following is the etiological agent of Rocky Mountain spotted fever: \nSelect and explain. \nA. R. rickettsia, B. Rochalimae quintana, C. R. tsutsugamushi, D. Coxiella burnetti', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., R. rickettsiaRef: Harrison, 19th/e, p. 1154; Ananthanarayan, 9th/e, p. 405)Rocky Mountain spotted fever is a bacterial infection transmitted by a tick. Serious damage to organs such as your kidneys and heart. Severe headache, high fever are important findings. A few days later, a rash usually appears on the wrists and ankles.", 'role': 'assistant'}]