This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamental concepts, Subject name: Anaesthesia
[{'content': 'All of the following factors decrease the minimum alveolar concentration (MAC) of an inhalational anaesthetic agent except \nSelect and explain. \nA. Hypothermia, B. Hyponatremia, C. Hypocalcemia, D. Anemia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: MINIMUM ALVEOLAR CONCENTRATION: The MAC of an inhaled anesthetic is the alveolar concentration that prevents movement in 50% of patients in response to a standardized stimulus (eg, surgical incision). MAC is a useful measure because it mirrors brain paial pressure, allows comparisons of potency between agents, and provides a standard for experimental evaluations. Ref: Miller&;s anesthesia 8th edition Ref: Morgan & Mikhail&;s clinical anesthesiology 6e', 'role': 'assistant'}]