Narrowest part of esophagus is at?
Ans. is 'a' i.e., Cricopharyngeal sphincter * The narrowest part of esophagus is its commencement at the cricopharyngeal sphincter.
Oesophagus
Cricopharyngeal sphincter
At the Aortic constriction
At the crossing of left principal bronchus
At the diaphragmatic opening
Cricopharyngeal sphincter