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': 'Scrub typhus is positive for \nSelect and explain. \nA. OX K, B. OX 2, C. OX K and OX 19, D. OX 19 only', 'role': 'user'}, {'content': "Answer: A \nExplanation: Scrub typhus aka chigger borne typhus is caused by orientia tsutsugamushi.In a heterephile agglutination test(weil Felix reaction), the sera of scrub typhus patients agglutinated only OX K strain of proteins mirabilis without getting agglutinated with OX 19 and OX 2 ...as some rickettsiae and ceain strains like OX K ,OX 19 and OX 2 of proteus share alkali stable carbohydrate antigen Ref: Ananthnarayan and paniker's microbiology 10th edition", 'role': 'assistant'}]