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': 'Catalase negative beta hemolytic streptacocci is - \nSelect and explain. \nA. Str. pneumoniae, B. Str. pyogenes, C. Str. aglactiae, D. Enterococcus', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Str. pyogenes", 'role': 'assistant'}]