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': 'All are true regarding scrub typhus except - \nSelect and explain. \nA. Caused by R tsutsugamushi, B. Spread by mites, C. Caused by bite of adult mite on vertebral host, D. Tetracycline is effective', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]