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: Unknown
Feline esophagus is: 
Select and explain. 
A. Eosinophilic esophagitis, B. GERD, C. Radiation esophagitis, D. Carcinoma esophagus
B: GERD
Answer: B: GERD 
Explanation: Ref. API Textbook of Medicine. Pg. 1690
 
Feline Esophagus

Feline esophagus also known as oesophageal shiver ,refers to the transient transverse bands seen in the mid  and lower esophagus on a double contrast barium swallow .
The appearance is almost always associated with active gastro-esophageal reflux and is thought to be due to contraction of muscularis muosa with resultant shortening of the esophagus and "bunching up" of mucosa in the lumen .