This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A male aged 60 years has foul breath. He regurgitates food that is eaten 3 days ago : Likely diagnosis is ? 
Select and explain. 
A. Zenkers diveiculum, B. Meckels diveiculum, C. Scleroderma, D. Achalasia cardia
A: Zenkers diveiculum
Answer: A: Zenkers diveiculum 
Explanation: Ans. is 'a' i.e., Zenker's diveiculum