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
Placement of a double lumen tube for lung surgery is best confirmed by – 
Select and explain. 
A. EtCO2, B. Airway pressure measurement, C. Clinically by auscultation, D. Bronchoscopy
D: Bronchoscopy
Answer: D: Bronchoscopy 
Explanation: ↵

Best confirmation of tracheal placement (i.e. detection whether tube is in trachea or esophagus) → capnography (end tidal CO2)
Best confirmation of double lumen tube placement (whether in trachea or bronchus) → flexible fibreoptic bronchoscopy.