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': 'Law under oath is not necessary for- \nSelect and explain. \nA. Wound certificate, B. Medical certificate, C. postmortem certificate, D. Expert opinion expressed in a treatise', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The oath is not necessary for an expert opinion expressed in a treatise.\nThe oath is, however, necessary in a wound certificate, a medical certificate, and a postmortem certificate.', 'role': 'assistant'}]