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': 'CSF is directly returned to venous system by: \nSelect and explain. \nA. Choroid plexus, B. Cerebral veins, C. Arachnoid villi, D. Emissary veins', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]