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: ENT
60 years old man with foul breath, Regurgitates food eaten 3 days ago, the likely diagnosis 
Select and explain. 
A. Loss of tone of upper esophageal sphincter, B. Zenker's Diverticulum, C. Achalasia cardia, D. Carcinoma esophagus
B: Zenker's Diverticulum
Answer: B: Zenker's Diverticulum 
Explanation: None