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': 'In case of chronic lead poisoning, the levels of which of the following is elevated: NIMHANS 11 \nSelect and explain. \nA. Porphobilinogen, B. 6-amino levulinic acid, C. Bilirubin, D. Urobilinogen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 6-amino levulinic acid', 'role': 'assistant'}]