This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oesophagus, Subject name: Surgery
A patient complaints of dysphagia, bad breath with regurgitation of food he had three day ago. Most likely cause is: 
Select and explain. 
A. Cancer esophagus, B. Zenker's diverticulum, C. Corrosive esophagus, D. DES
B: Zenker's diverticulum
Answer: B: Zenker's diverticulum 
Explanation: Ans. (b) Zenker diverticulumRef Sabiston 20th Edition, Page 1022* Zenker's Diverticulum: Most common symptom is dysphagia* It is also associated with Halitosis and Regurgitation.* Due to stagnation of food in the diverticulum patient may regurgitate after long period.* Treatment is Diverticulectomy or Dohlman operation