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': 'A patient presents to the emergency depament with bluish discolouration of conjunctiva, mucus membranes and nails one hour after ingestion of a poison. Examination reveals tachycardia and hypotension. Which of the following is the most likely ingested substance? \nSelect and explain. \nA. Mercury, B. Arsenic, C. Lead, D. Silver', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Presence of bluish discolouration of conjunctiva, mucus membranes and nails suggests cyanosis. Cyanosis together with peripheral vascular failure and shock within one hour of ingestion of a poison suggests Acute Arsenic poisoning of the Fulminant type. Ref: The Essentials of Forensic Medicine and Toxicology By K.S Narayan Reddy, 29th Edition, Page 482; Recognition and Management of Pesticide Poisonings (5th Ed.) By J. Routt Reiga, Pages 127-30', 'role': 'assistant'}]