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. H2504, D. Cannabis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Carbolic acid', 'role': 'assistant'}]