This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
The formation of 25-hydroxycholecalciferol takes place in the - 
Select and explain. 
A. Liver, B. Kidney, C. Intestines, D. Pancreas
A: Liver
Answer: A: Liver 
Explanation: None