This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 2, Subject name: Forensic Medicine
[{'content': 'Which of the chemical is used in forgery for removing ink? \nSelect and explain. \nA. Oxalic acid, B. Acetic acid, C. Formic acid, D. Ammonia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Oxalic acid is used in cleaning iron rust, bleaching & dyeing. Ink remover solutionQin cases of forgery.', 'role': 'assistant'}]