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
The following is the etiological agent of Rocky mountain spotted fever: 
Select and explain. 
A. Rickettsia rickettsii, B. Rochalimaea quintana, C. Rickettsia tsutsugamushi, D. Coxiella burnetii
A: Rickettsia rickettsii
Answer: A: Rickettsia rickettsii 
Explanation: Ans. is 'a' i.e., Rickettsia Rickettsi SpeciesDiseaseVectorR. ProwazekiiEpidemic typhusLouseR. ProwazekiiBrill Zinsser diseaseLouseR. typhiEndemic typhusRat fleaR. RickettsiaRocky mountain spotted feverTickR. akariRickettsial poxGamasid miteOriental TsutsugamushiScrub typhusTrombiculid mite