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: Dental
[{'content': 'Central gram negative core supporting outer coccal cells is called: \nSelect and explain. \nA. Bristle brush arrangement, B. Corncob arrangement, C. Bottle brush arrangement, D. Hourglass arrangement', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]