Ans is D i.e. Out pouching of the anterior pharyngeal wall, just above the cricopharyngeus muscle Zenker's diveiculum is out pouching of the posterior pharyngeal wall, where pharyngeal mucosa herniates through the Killian's dehiscence (the weak area between the upper oblique fibres and the lower horizontal fibres of the inferior constrictor muscle). Zenker's diveiculum is an acquired diveiculum and not a congenital diveiculum. It's a false diveiculum as it does not contain all the anatomic layers of the oesophageal wall. Barium swallows are diagnostic. Lateral views are essential as these are posterior outpouchings.