This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 2, Subject name: Forensic Medicine
One of the poisons can be detected even from burnt bones 
Select and explain. 
A. OPC, B. LSD, C. cyanide, D. Arsenic
D: Arsenic
Answer: D: Arsenic 
Explanation: Bone, hair and nails are preserved in Heavy metals poisonings like arsenic, antimony, and thallium. Distribution of Arsenic in the body: * Arsenic is present in almost all tissues, and found in the greatest quantity in the liver, followed by kidneys and spleen. In cases, where the patient survives, it is found in the muscles (for months), bones, hair, nails and skin (Sulfhydryl groups in keratin) for years. Hair: Arsenic > 75 ug% - Poisoning. * Nails: Presence of > 100 ug% of arsenic - Poisoning.