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
A 40-year-old female patient presented with dysphagia to both liquids and solids and regurgitation for 3 months. The dysphagia was non-progressive. What is the most likely diagnosis? 
Select and explain. 
A. Caricnoma of the esophagus, B. Lower oesophageal mucosal ring, C. Achalasia cardia, D. Reflux esophagitis with esophageal stricture
C: Achalasia cardia
Answer: C: Achalasia cardia 
Explanation: Dysphagia equal for both solids and liquids from the very onset of disease suggests motor disorder like 
Achalasia
Diffuse esophageal spasm
Dysphagia more for solids than liquids implies mechanical obstruction
Ca esophagus
Strictures
Webs
Note that dysphagia in achalasia cardia is slowly progressive. But 'nonprogressive' dysphagia in this pt. does not rule out the diagnosis of achalasia