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': 'Streptococci causing dental caries: \nSelect and explain. \nA. Streptococci equisimilis, B. Streptococci mutans, C. Streptococci pneumoniae, D. Streptococci bovis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Streptococci mutans S. mutans: It is member of viridans streptococci (a-hemolytic) which is pa of the normal flora of the oral cavity. It assumes bacillary form in acid environment. Can synthesize acid and large polysaccharide (adhesive dextran or levan) from sucrose.', 'role': 'assistant'}]