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
What is the most reliable site to measure core temperature during general anesthesia? 
Select and explain. 
A. Pulmonary aery, B. Distal esophagus, C. Rectum, D. Tympanic membrane
D: Tympanic membrane
Answer: D: Tympanic membrane 
Explanation: Ans: D. Tympanic membrane(Ref Miller's 7/e p1550)Though pulmonary aery is the gold standard site for core temperature measurement, esophagus has similar reliability and is the most commonly used site in the anesthetic practice fior temperature monitoring.Core-Temperature Monitoring:Sites for Core Temperature MeasurementGold standard site for core temperature measurementPulmonary aeryMost accurate for brain temperatureTympanic membraneBest for brain temperatureNasopharynxBest site & most commonly used for core body temperatureLower end of esophagus