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': 'Tetany is caused by which poisoning : \nSelect and explain. \nA. Oxalic acid, B. Carbolic acid, C. Sulphuric acid, D. Nitric acid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Oxalic acid combines with calcium and causes its withdrawal from them causing hypocalcemia.\nIn acute poisoning by oxalic acid, it produces hypocalcemia leading to muscle irritability, tetany & convulsions.', 'role': 'assistant'}]