<prompt> B-ring in oesophagus is found at?Junction of cervical esophagus and cricopharyngeusGastro-esophageal junctionJunction of upper 13rd and middle 13rd of esophagusJunction of cricopharyngeus and upper 13rd of esophagus  <response>: B- ring - Schatzki ring Lower 13rd esophageal mostly at the Gastro - esophageal junction LE Ring 13mm Aphagia Food impaction 