This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestine, Subject name: Medicine
[{'content': 'Which of the following is produced by Argentaffi- noma of ileum? \nSelect and explain. \nA. G.A.B.A., B. Serotonin, C. Epinephrine, D. Nor-epinephrine', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. 'b' i.e. Serotonin o Argentaffin cells of the carcinoid produce serotonin.o The metabolites of serotonin are 5HIAA and are used in the diagnosis of carcinoid syndrome.", 'role': 'assistant'}]