This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and Reproduction, Subject name: Physiology
[{'content': 'Active from of vitamin D is: \nSelect and explain. \nA. Cholecalciferol, B. 24, 25 (OH) 2 Vit-D, C. 1, 25 (OH) 2 Vit-D, D. 25-OH Vit-D', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) 1, 25 (OH) 2 Vit-D(Ref: Ganong, 25th ed/p.377)The active form of vitamin D is called 1, 25- dihydroxycholecalciferol or calcitriol', 'role': 'assistant'}]