<prompt> What is the commonest site of esophageal carcinoma ?lower end of oesophagusupper end of oesophagusmiddle third of oesophagusthorasic pa of oesophagus  <response>: The lower end of the oesophagus is also prone to inflammation or ulceration by regurgitation of acid from the stomach. It is the commonest site of oesophageal carcinoma. Ref : B D Chaurasias Human Anatomy , seventh edition , volume 2 , pg.no.,273. 