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 of the areas of the tooth is most sensitive during cavity preparation? \nSelect and explain. \nA. Enamel (anterior teeth), B. Enamel (Posterior teeth), C. Dentin, D. Dentinoenamel junction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]