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: Dental
[{'content': 'Micro organism which uses steroids as growth factor is \nSelect and explain. \nA. P.gingivalis, B. P.intermedia, C. S.sanguis, D. S.mutans', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]