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: Anatomy
[{'content': 'Distance of the Lower Esophageal Sphincter from the upper incisors is - \nSelect and explain. \nA. 15cm, B. 22.5cm, C. 27.5cm, D. 37.5cm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: There are 4 esophageal constrictions. They are at 15cms, 22.5cms, 27.5cms and 37.5 to 40 cms, from the incisors. The fourth constriction is when the esophagus pierces the diaphragm, and here the lower esophageal sphincter is there.', 'role': 'assistant'}]