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 of the following structures, found external\nto the bacterial cell wall, are involved in bacterial\nattachment to cell surfaces? \nSelect and explain. \nA. Capsule, B. Flagella, C. Pill, D. Mesosomes', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]