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
The triad of alopecia, neuropathy and diarrhoea results from 
Select and explain. 
A. Thallium, B. Mercury, C. Dathura, D. Opium
A: Thallium
Answer: A: Thallium 
Explanation: Thallium Poisoning * Ideal homicidal poison features * Features resemble natural disease, Gullain Barre syndrome * Mees lines present * Triad of alopecia, neuropathy and diarrhea * Pseudomotor neuropathy