A 45-year-old male presents with a 6-month history of progressive dysphagia to both solids and liquids, non-cardiac chest pain, and regurgitation of undigested food. Barium swallow demonstrates esophageal dilation with a "bird's beak" appearance at the distal esophagus. What is the most likely diagnosis?
✓ Correct Answer: Option B
The classic triad of dysphagia to both solids and liquids, non-cardiac chest pain, regurgitation, and the "bird's beak" appearance on barium swallow are highly characteristic of achalasia, a primary esophageal motility disorder.