This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intravenous Anesthetic Agents, Subject name: Anaesthesia
Which of the following intravenous anaesthetic agent has extrahepatic additional route of metabolism - 
Select and explain. 
A. Thiopentone, B. Propofol, C. Etomidate, D. Ketamine
B: Propofol
Answer: B: Propofol 
Explanation: The clearance rate of Propofol exceeds hepatic blood flow, suggesting that an extrahepatic route of elimination also contribution its clearance. since propofol has extrahepatic and extrarenal route of metabolism its metabolism is never delayed in hepatic and renal failure.