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
CSF is directly returned to venous system by: 
Select and explain. 
A. Choroid plexus, B. Cerebral veins, C. Arachnoid villi, D. Emissary veins
C: Arachnoid villi
Answer: C: Arachnoid villi 
Explanation: None