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
Drugs that can be used safely in porphyria are: a) Phenobarbitone b) Ketamine c) Sodium valproate d) Midazolam e) Pethidine 
Select and explain. 
A. de, B. ae, C. ad, D. bc
A: de
Answer: A: de 
Explanation: None