This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Forensic Medicine
Buonian line is seen in poisoning 
Select and explain. 
A. Lead, B. Arsenic, C. Copper, D. Silver
A: Lead
Answer: A: Lead 
Explanation: Chr. Lead poisoning = Plumbism = Saturnism = Saturnine poisoning- ALA in urine, Coproporphyrin in urine, facial pallor, Basophilic stippling/Punctate basophilia (dark blue, pin-head spots in cytoplasm of RBCs), Buonian line (blue line gums' margin, PbS, 50-70% cases, near carious/diy teeth, Lead palsy, Pb encephalopathy, wrist drop, foot drop, Colic, Constipation, Menstrual irregularity, Sterility, Nephropathy, X-ray- radio-opaque bands at metaphyses of long bones, Pb >0.03mg% in blood is diagnostic.) Ref: Krishnan vij Textbook of Forensic Medicine and Toxicology; 5th ed; Page no: 469