This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Forensic Medicine
[{'content': 'All of the following are preserved in a case of poisoning except \nSelect and explain. \nA. Stomach with its contents, B. A loop of large intestine, C. Blood, D. Urine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (B) A loop of large Intestine', 'role': 'assistant'}]