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': 'A protoplast is best characterized as a bacterial cell: \nSelect and explain. \nA. With a cell wall but free of a capsule, B. Containing a cell wall and a capsule, C. Free of a cell wall and a capsule, D. Uniquely sensitive to penicillin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]