This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
During induction of general anesthesia, administration of oxygen with high concentration of nitrous oxide and halothane hastens the uptake of halothane, this is known as 
Select and explain. 
A. Fink effect, B. Concentration effect, C. Second gas effect, D. Third gas effect
C: Second gas effect
Answer: C: Second gas effect 
Explanation: During induction ofgeneral anesthesia, when a large volume of a gas (nitrous oxide) is taken up from alveoli into pulmonary capillary blood, the concentration of gases remaining in the alveoli is increased. This results in effects known as the second gas effect. These effects occur because of the contraction of alveolar volume associated with the uptake of the nitrous oxide. this effect makes speed of induction fast