This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CT SCAN, Subject name: Radiology
[{'content': 'Hounsfield unit of CSF in ventricles is generally \nSelect and explain. \nA. -1000 HU, B. -100 HU, C. 0 HU, D. 70 HU', 'role': 'user'}, {'content': 'Answer: C \nExplanation: CSF/ water has HU of 0 and is taken as a reference value -1000 HU Is Air -100 HU is Fat 0 HU is CSF/Water 70 HU is acute bleed 130 HU is Contrast 200-250 HU is Calcifications above 400-1000 HU is coical bone.', 'role': 'assistant'}]