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
In chronic lead poisoning, diagnostic increase in levels of: September 2004 
Select and explain. 
A. Bile, B. Calcium, C. Urobilinogen, D. Coproporphyrin III
D: Coproporphyrin III
Answer: D: Coproporphyrin III 
Explanation: Ans. D i.e. Coproporphyrin III