This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Griffith typing is done for \nSelect and explain. \nA. Staphylococcus, B. Streptococcus, C. Meningococcus, D. Gonococcus', 'role': 'user'}, {'content': "Answer: B \nExplanation: Griffith typing is used for fuher classification of S.pyogenes, belonging to Lancefield's group A. Based on the M proteins on the cell surface, they are subdivided into M types. About 80 types of Streptococcus pyogenes have been recognized so far (types M1, M2, M3 and so on). Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 211", 'role': 'assistant'}]