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 general anaesthetic agent has the least analgesic action? 
Select and explain. 
A. N2O, B. Halothane, C. Ether, D. Propane
B: Halothane
Answer: B: Halothane 
Explanation: Halothane is a potent inhalational anaesthetic but is not a good analgesic or muscle relaxant. It potentiates the effect of competitive neuromuscular blockers.