This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Anaesthesia
Endotracheal tube in the esophagus is best assessed by: 
Select and explain. 
A. Chest wall movement, B. Auscultation, C. CO2 Exhalation, D. Chest tube passes through vocal cords
C: CO2 Exhalation
Answer: C: CO2 Exhalation 
Explanation: For sure shot confirmation of endotracheal tube Capnography is used. ET tube in trachea (capnography) While if almost Flat line appears - Et tube is in esophagus.