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': 'Poison having local action only: \nSelect and explain. \nA. Sulphuric acid, B. Carbolic acid, C. Oxalic acid, D. Phosphorus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Sulphuric acid', 'role': 'assistant'}]