A68-year-old man who has smoked for at least 50 years reports that lately he feels as though food is "getting stuck" in his throat. at first this was a problem just with dry food, but now his morning oatmeal is getting stuck. on questioning, he reports drinking at least five alcoholic beverages nearly every day. his problem is most likely:
a) achalasia. b) squamous cell carcinoma of the esophagus. c) dysphagia secondary to scleroderma. d) gastrointestinal reflux disease.