This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pathology
[{'content': 'Which neuroendocrine tumour causes biliary obstruction \nSelect and explain. \nA. Somatostatinoma, B. Gastrinoma, C. Insulinoma, D. VIPoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A gastrinoma is a tumor in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum, stomach and the small intestine. There is hypersecretion of HCl acid into the duodenum, which causes the ulcers', 'role': 'assistant'}]