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 with suspected poisoning has brownish oral mucosa and tongue, constricted pupil and greenish brown urine, poisoning is with - \nSelect and explain. \nA. Carbolic acid, B. Morphine, C. H2SO4, D. Cannabis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Brownish oral mucosa and tongue (due to corrosion), constricted pupil and greenish brown urine is seen in carbolic acid (phenol) poisoning.', 'role': 'assistant'}]