This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: Anatomy
[{'content': 'Not a normal variant of intracranial venous drainage:- \nSelect and explain. \nA. Inferior sagittal sinus, B. Median prosencephalic vein, C. Occipital sinus, D. Marginal sinus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Abnormal variant: - Median prosencephalic vein: - Formation of vein of Galen got compromised. d/t aerio-venous fistula Dural venous sinuses: - Internal cerebral vein (draining blood around the brainstem) joins with basal vein of Rosenthal to form the great vein of Galen. Great cerebral vein (vein of Galen) joins with inferior sagittal sinus to form straight sinus, which drain into confluence of sinus. Confluence of sinus - 3 incomings: Mnemonic - SOS (draining into confluence) anteriorly - straight sinus below - occipital sinus superiorly - superior sagittal sinus This confluence drains into Right & left transverse venous sinuses | Sigmoid sinuses | IJV', 'role': 'assistant'}]