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: Pharmacology
[{'content': 'Drugs that can be used safely in porphyria are: a) Phenobarbitone b) Ketamine c) Sodium valproate d) Midazolam e) Pethidine \nSelect and explain. \nA. de, B. ae, C. ad, D. bc', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]