This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mycobacterial Infections, Subject name: Dental
[{'content': 'Buruli ulcer is caused by? \nSelect and explain. \nA. M. marinum, B. M. ulcerans, C. M. avium intercellulare, D. M. tuberculosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Buruli ulcer is caused by Mycobacterium ulcerans. Ulcers may be very deep and involve muscle and bone. Skin test with burulin gives positive response.', 'role': 'assistant'}]