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': "Weil's zone of pulp is \nSelect and explain. \nA. Cell degenerated zone, B. Cell rich zone, C. Cell regenerated zone, D. Cell free zone", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]