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': 'Pigment producing atypical mycobacteria - \nSelect and explain. \nA. M. fortuitum and M. chelonae, B. M. xenopi and MAC, C. M. gordonae and M. szulgai, D. M. ulcerans', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pigment producing atypical mycobacteria:\n\nPhotochromogen: M marinum, M simiae, M. asciaticum, M kansasii,\nScotochromogen: M. scrofulaceum, M szulgai, S.gordonae', 'role': 'assistant'}]