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
Pain insensitive structure in brain is - 
Select and explain. 
A. Falx cerebri, B. Dural sheath surrounding vascular sinuses, C. Middle meningeal artery, D. Choroid plexus
D: Choroid plexus
Answer: D: Choroid plexus 
Explanation: None