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: Physiology
Function of ADH is: 
Select and explain. 
A. Water reabsorption, B. Water excretion, C. Na+ absorption, D. K+ secretion
A: Water reabsorption
Answer: A: Water reabsorption 
Explanation: None