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': 'Which of the following is most frequently associated with the typical form of carcinoid syndrome ? \nSelect and explain. \nA. Foregut carcinoid, B. Midgut carcinoid, C. Hindgut carcinoid, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Midgut carcinoids are argentaffin-positive and have a high serotonin content. They most frequently cause the typical carcinoid syndrome when they metastasize. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 3058', 'role': 'assistant'}]