This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'The level of circula ng 1,25- dihydroxycholecalciferol is significantly reduced in patients with chronic liver disease because \nSelect and explain. \nA. The liver can no longer efficiently conve 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, B. The liver can no longer efficiently conve vitamin D to cholecalciferol, C. The liver can no longer efficiently conve vitamin D to 25- hydroxycholecalciferol, D. The liver can no longer efficiently conve cholecalciferol to 1,25-dihydroxycholecalciferol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A healthy liver conves vitamin D (cholecalciferol) to form 25-hydroxycholecalciferol, but a diseased liver has a reduced capacity to do so. The kidney, not the liver, is responsible for the conversion of 25 hydroxycholecalciferol to 1,25-dihydroxycholecalciferol. Vitamin D, not 1,25-hydroxycholecalciferol, is absorbed by the small intestine.', 'role': 'assistant'}]