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: Radiology
Rat – tail appearance on barium swallow examination is seen in – 
Select and explain. 
A. Achalasia cardia, B. Carcinoma esophagus, C. Hiatus hernia, D. Diffuse esophageal spasm
B: Carcinoma esophagus
Answer: B: Carcinoma esophagus 
Explanation: "Rat-tail" appearance on barium study is seen in carcinoma esophagus.