This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiology Q Bank, Subject name: Radiology
[{'content': 'A 24yr old female with history of easy fatigabality,dysphagia. Oral ulcers and oesophageal webs are shown on endoscopy. What is most common site for the oesophageal webs? \nSelect and explain. \nA. Upper end of esophagus, B. Lower end of esophagus, C. Middle layer of esophagus, D. Lateral wall of esophagus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Esophageal webs :- - refer to an esophageal constriction caused by a thin mucosal membrane projecting into the lumen. - M/c in women - located in upper esophagus (cervical esophagus) - can be seen on frontal and lateral views on Xray - pt. may remain asymptomatic, but if the stenosis is severe enough causes dysphagia and regurgitation - arises from anterior wall and never from posterior wall - is associated with plummer wilson syndrome - these are associated with risk of carcinoma(post cricoid)', 'role': 'assistant'}]