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': 'Which component of St. pyogenes has cross reactivity with synovium of human ? \nSelect and explain. \nA. Capsular hyaluronic acid, B. Cell proteins, C. Group A carbohydrate antigens, D. Peptidoglycan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]