<prompt> A coin is struck at 25 cm from incisor in the esophagus, this place coincides with -Cricopharyngeal junctionBronchus bifurfationAortic archOesophago-gastric junction  <response>: Ans-C Barium swallow may show a constriction at three site : QCricopharyngeal junction - Narrowest point 15 cm from incisor QMiddle narrowing - crossing of the left main stem bronchus and aortic arch 25 cm from incisor. QLower most narrowing - At the hiatus of the diaphragm 40 cm from incisor 