This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
[{'content': 'Foramen of Magendie is the central opening of \nSelect and explain. \nA. Lateral ventricle, B. 4th ventricle, C. 3rd ventricle, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Foramen of magendie is an opening in the roof of 4th ventricle through which the cavity of ventricle communicates with the subarachnoid space of the cerebellomedullary cistern.(Ref: vishram Singh textbook of clinical neuroanatomy,2nd edition page 121)', 'role': 'assistant'}]