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
Streptococci causing dental caries: 
Select and explain. 
A. Streptococci equisimilis, B. Streptococci mutans, C. Streptococci pneumoniae, D. Streptococci bovis
B: Streptococci mutans
Answer: B: Streptococci mutans 
Explanation: 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.