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: Anatomy
[{'content': 'True about 4thventricle is- \nSelect and explain. \nA. Rhomboid fossa forms floor, B. Choroid plexus lies at its floor, C. Connection between two cerebral hemispheres, D. Lies inferior to inferior cerebellar peduncle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e., Rhomboid fossa forms the floor', 'role': 'assistant'}]