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': 'The disadvantages of a complete ceramic crown include \nSelect and explain. \nA. Reduced strength of the restoration, B. Need for a shoulder-type margin circumferentially, C. Porcelain brittleness, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]