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
[{'content': 'MAC is not affected by all of the following except? \nSelect and explain. \nA. Species, B. Sex, C. Duration of anaesthesia, D. Age', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 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', 'role': 'assistant'}]