This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroanatomy, Subject name: Anatomy
[{'content': 'The blockage of which of the following blood vessel will lead to medial medullary syndrome? \nSelect and explain. \nA. A, B. B, C. C, D. D', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B BThe following diagram and its branches should be remembered.', 'role': 'assistant'}]