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
Which of the following anaesthetic agent lacks analgesic effect – a) N2Ob) Thiopentonec) Methohexitoned) Ketaminee) Fentanyl 
Select and explain. 
A. a, B. c, C. ac, D. bc
D: bc
Answer: D: bc 
Explanation: Barbiturates (methexitone, thiopentone) do not have analgesic action. Rather they can cause hyperalgesia.