Endoscopy is contraindicated in: (A) Achalasia, (B) Peptic stricture, (C) Esophageal carcinoma, (D) Esophageal web
Answer is A. Endoscopy is C/I in regurgitant lesions like Achalasia and Zenker's diverticulum as it carries the risk of rupture in mediastinum (Very risky).