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': 'Which type of cervical finish line prepared will result in \nan overcontoured restoration? \nSelect and explain. \nA. Chamfer, B. Knife-edge, C. Shoulder, D. Shoulder with bevel', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Knife-edge margin provides inadequate bulk for the material and underpreparation. Overcontoured crowns result mainly due to underprepared teeth.', 'role': 'assistant'}]