Vein of Galen drains into-

Ans. is 'a' i.e., Straight sinus * Great cerebral vein of Galen: It is formed by the union of two internal cerebral veins, is 2 cm long and drains into the straight sinus. Its tributaries are:- (a) Internal cerebral veins, (b) Basal veins, (c) Occipital veins, (d) Posterior callosal vein