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
Maximum analgesic action found in – 
Select and explain. 
A. Catecholamine, B. Propofol, C. Ketamine, D. Thiopentone
C: Ketamine
Answer: C: Ketamine 
Explanation: Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action.