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
The most reliable dental change used in Gustafson's method for age estimation is: COMEDK 08; AIIMS 11 
Select and explain. 
A. Attrition, B. Cementum, C. Secondary dentin deposition, D. Transparency of root
D: Transparency of root
Answer: D: Transparency of root 
Explanation: Ans. Transparency of root