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
[{'content': "Regarding Schatzki's ring the true statement is: \nSelect and explain. \nA. Has skeletal muscle, B. Located at upper esophagus, C. Located at lower esophagus, D. Contain all layers of esophagus", 'role': 'user'}, {'content': "Answer: C \nExplanation: Schatzki's ring is a lower esophageal mucosal ring May result from GERD Asymptomatic 10% Cause dysphagia Ref: Bailey & Love, 25th Edition, Pages 1041", 'role': 'assistant'}]