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: Physiology
[{'content': 'Tumor of which of the following type of cells result in Zollinger Ellison syndrome? \nSelect and explain. \nA. ECL cells, B. Chief cells, C. G cells, D. S cells', 'role': 'user'}, {'content': "Answer: C \nExplanation: Zollinger Ellison syndrome is a malignancy of the gastrin secreting G cells present in the antral mucosa of the stomach. Parietal cells secrete acid and intrinsic factor, chief cells secretes pepsinogen, ECL cells synthesize histamine, and secretin is synthesized by the S cells of the duodenum. Ref: LANGE'S Gastrointestinal Physiology By Kim E Barrett chapter 3.", 'role': 'assistant'}]