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': 'Sipple syndrome is also known as:- \nSelect and explain. \nA. MEN 1, B. MEN 2a, C. MEN 26, D. None of the Above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (MEN 2a): Sipple syndrome refers to MEN Type-HA', 'role': 'assistant'}]