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: Medicine
[{'content': 'In gastric outlet obstruction in a peptic ulcer patient the site of obstruction is most likely to be : \nSelect and explain. \nA. Antrum, B. Duodenum, C. Pylorus, D. Pyloric canal', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (Duodenum) Gastric outlet obstruction in a patient with peptic ulcer disease is suggestive of pyloric stenosis. The term pyloric stenosis is normally a misnomer. The stenosis is seldom at the pylorus. Commonly the stenosis is found in the first pa of the duodenum, the most common site for a peptic ulcer.', 'role': 'assistant'}]