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: Forensic Medicine
[{'content': "The most reliable dental change used in Gustafson's method for age estimation is: COMEDK 08; AIIMS 11 \nSelect and explain. \nA. Attrition, B. Cementum, C. Secondary dentin deposition, D. Transparency of root", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Transparency of root', 'role': 'assistant'}]