This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anaesthesia
Which of the following is fastest acting inhalational anaesthetic agent? 
Select and explain. 
A. Halothane, B. Desflurane, C. Sevoflurane, D. Isoflurane
B: Desflurane
Answer: B: Desflurane 
Explanation: (Refer: Morgan and Mikhail's Clinical Anaesthesiology, 5th edition, pg no.170-171)