ENT Oesophagus ea1af825 Narrowest part of esophagus is at? A Cricopharyngeal sphincter B At the Aortic constriction C At the crossing of left principal bronchus D At the diaphragmatic opening High-Yield Explanation Ans. is 'a' i.e., Cricopharyngeal sphincter * The narrowest part of esophagus is its commencement at the cricopharyngeal sphincter.