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
[{'content': 'Placement of a double lumen tube for lung surgery is best confirmed by – \nSelect and explain. \nA. EtCO2, B. Airway pressure measurement, C. Clinically by auscultation, D. Bronchoscopy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ↵\n\nBest confirmation of tracheal placement (i.e. detection whether tube is in trachea or esophagus) → capnography (end tidal CO2)\nBest confirmation of double lumen tube placement (whether in trachea or bronchus) → flexible fibreoptic bronchoscopy.', 'role': 'assistant'}]