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': 'Capsule of pneumococcus is: \nSelect and explain. \nA. Polypeptide, B. Polysaccharide, C. Lipopolysaccharide, D. Not a Virulence factor', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Polysaccharide', 'role': 'assistant'}]