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
Cork–screw opperance of esophagus is seen – 
Select and explain. 
A. Achalasia cardia, B. Carcinoma esophagus, C. Diffuse esophageal spasm, D. Caustic injury
C: Diffuse esophageal spasm
Answer: C: Diffuse esophageal spasm 
Explanation: Esophageal curling/corkscrew oppearance is seen in diffuse esophageal spasm.