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
True about great cerebral vein of galen 
Select and explain. 
A. Thalamostriate vein and choroidal vein form the great cerebral vein of galen, B. It forms superficial venous drainage system of brain, C. Great cerebral vein of galen drains into sigmoid  sinus, D. Basal vein and deep cerebral vein unite beneath splenium of corpus callosum to form vein of galen
D: Basal vein and deep cerebral vein unite beneath splenium of corpus callosum to form vein of galen
Answer: D: Basal vein and deep cerebral vein unite beneath splenium of corpus callosum to form vein of galen 
Explanation: Great cerebral vein constitutes deep vein system of brain. It drains into straight sinus.
Thalamostriate vein and choroidal vein join to form internal cerebral vein (deep cerebral vein).