This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Weil felix reaction for Scrub typhus shows positivity for - \nSelect and explain. \nA. OX-K, B. OXK + OX19, C. OX-2, D. OX-19', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]