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
Maximum dilatation of esophagus occurs in? 
Select and explain. 
A. Carcinoma at gastro esophageal junction, B. Achalasia cardia, C. Stricture at lower end, D. CREST syndrome
B: Achalasia cardia
Answer: B: Achalasia cardia 
Explanation: Ans. is 'b' i.e. Achalasia cardia