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 is C/I in closed system anaesthesiology – 
Select and explain. 
A. Methoxyflurane, B. Isoflurane, C. Sevoflurane, D. Desflurane
C: Sevoflurane
Answer: C: Sevoflurane 
Explanation: Sevoflurane forms compound 'A' (nephrotoxic) with sodalime & baralyme, therefore should not be used in closed system.