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': 'Brown discolouration of the mucosa of the stomach is seen in poisoning due to : \nSelect and explain. \nA. Nitric acid, B. Sulphuric acid, C. Hydrochloric acid, D. Mercury', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. H2SO4', 'role': 'assistant'}]