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: Pathology
[{'content': 'Which of the following would be least likely to cause an ulcer in distal esophagus? \nSelect and explain. \nA. HSV, B. Achalasia cardia, C. Severe reflux esophagilis, D. Zenkers diverticulum', 'role': 'user'}, {'content': "Answer: D \nExplanation: Zenkers diverticulum occurs at the junction of thyro and cricopharyngeus i.e above the esophagus it doesn't cause ulcer in distal esophagus.", 'role': 'assistant'}]