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
Second gas effect is ? 
Select and explain. 
A. Displacement of N20 by Oxygen, B. Displacement of oxygen by N20, C. Facilitation of inhalation of Halothane by N20, D. Removal of oxygen by N20 from alveoli during recovery from general anaesthesia
C: Facilitation of inhalation of Halothane by N20
Answer: C: Facilitation of inhalation of Halothane by N20 
Explanation: Ans. is 'c' i.e., Facilitation of inhalation of halothane by N20