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: Medicine
A lady presented with non progressive dysphagia only for solids. Barium study showed proximal esophageal dilatation with distal constriction. The most likely diagnosis is. 
Select and explain. 
A. Peptic Stricture, B. Carcinoma Esophagus, C. Achalasia Cardia, D. Lower Esophageal Ring
D: Lower Esophageal Ring
Answer: D: Lower Esophageal Ring 
Explanation: Answer is D (Lower esophageal ring) Non progressive (episodic) dysphagia only for solids is characteristic of lower esophageal rings (Schatzki's ring). The ring is apparent as a constriction in the lower esophagus on barium swallow. Peptic stricture and carcinoma esophagus present with progressive dysphagia for solids while Achalasia presents with progressive dysphagia for both solids and liquids.