This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
CSF is formed by - 
Select and explain. 
A. Arachnoid villi, B. Venous plexus, C. Choroid plexus, D. Subfornical nucleus
C: Choroid plexus
Answer: C: Choroid plexus 
Explanation: Ans. (c) Choroid plexus(Ref: Ganong, 25th ed/p.603)CSF is produced from choroid plexuses epithelial cells. It is absorbed through the arachnoid villi into veins