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
MAC is not affected by all of the following except? 
Select and explain. 
A. Species, B. Sex, C. Duration of anaesthesia, D. Age
D: Age
Answer: D: Age 
Explanation: MAC decreases with age. Excluding patients < 1 year of age every decade there is 6% decrease in value of MAC. Endocrine disorders, duration of anaesthesia, species ,sex does not affect MAC