This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'All are true about streptococcus Except \nSelect and explain. \nA. M-protein is responsible for production of mucoid colonies, B. M-protein is responsible for virulence, C. Mucoid colonies are virulent, D. Classified based on their haemolytic propeies.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mucoid colonies are due to the production of the capsule of hyaluronic acid not due to M-protein. Growth characteristic of Strep. pyogenes: On blood agar, virulent stains form matt or mucoid colonies while avirulent from glossy colonies. M, T, R are proteins found on the outer pa of the cell wall and forms the basis of Griffith classification. M protein - acts as virulence factor and antibody against it is protective. T and R protein - No relation to virulence Ref : 208', 'role': 'assistant'}]