This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2017, Subject name: Forensic Medicine
Black foot is seen in which poisoning? 
Select and explain. 
A. Arsenic, B. Lead, C. Mercury, D. Phosphorus
A: Arsenic
Answer: A: Arsenic 
Explanation: Black foot disease is caused by arsenic poisoning since it causes thrombosis of vessels and may cause peripheral gangrene. Mnemonic Arsenic poisoning A - Anemia / Aldrich Mee's line / Arsenophagist (Tolerate upto 300mg ) R - Rain drop pigmentation / Reinsch test / Red velvety mucosa S - Sub endocardial hemorrhages / Sensory neuropathy E - Eruptions N - NAA I - Imbibition of arsenic ( Arsenic imbibed from surrounding soils after death ) / before treated iron oxide C - Cumulative poison / Cholera like symptom / Chelation for treatment