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: Anaesthesia
[{'content': 'In porphyria all drugs are safe except – \nSelect and explain. \nA. Propofol, B. Midazolam, C. Afentanyl, D. Pentazocin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pentazocin is considered unsafe, but other opioids including morphine, codeine, pethidine, fentanyl, Alfentanil and naloxone have been used safely. Propofol and benzodiazepines (midazolam) are safe.', 'role': 'assistant'}]