This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
Pain insensitive structure in brain is 
Select and explain. 
A. Falx cerebri, B. Dural she ath surrounding vascular sinuses, C. Middle meningeal aery, D. Choroid plexus
D: Choroid plexus
Answer: D: Choroid plexus 
Explanation: Pain Insensitive structures in Brain :Brain parenchymaEpendymaChoroid plexusPia matterArachnoidDura over convexity of skull ( Dura around vascular sinuses and vessels is sensitive to pain)Pain Sensitive structures in Brain :Cranial venous sinuses with afferent veinsAeries at base of brain and aeries of dura including middle meningeal aery.(Ref: Gray&;s anatomy, page 404)