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': 'Not a pathogenic mycobacterium - \nSelect and explain. \nA. M. paratuberculosis, B. M. kansasii, C. M. ulcerans, D. M. intracellulare', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., M. paratuberculosis", 'role': 'assistant'}]