A patient presents with increasing retrosternal pain and dysphagia for both solids and liquids over 18 months but denies weight loss. Chest is clear. What is the most likely diagnosis?

The key is C. Esophageal spasm. [DES manifests as intermittent difficulty swallowing (dysphagia) for solid foods and liquids, and atypical chest pain. The chest pain may appear similar to cardiac chest pain (angina pectoris). In achalasia there is chest findings of aspiration pneumonia and weight loss. So this is unlikely to be achalasia].