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': 'Most impoant investigation for diagnosis of Zollinger Ellison syndrome is: March 2013 \nSelect and explain. \nA. Ca2+ infusion test, B. Secretin injection test, C. ACTH stimulation test, D. Steroid assay', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B i.e. Secretin injection test Gastrinoma/ ZES MC site: Duodenum Non beta cell tumour, Neuro-endocrine tumour/ NET secreting: Gastrin Most impoant investigation: Secretin injection test DOC for ZES: Proton pump inhibitors Hepatic metastasis occurs (33%)', 'role': 'assistant'}]