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
The primary site of action of antidiuretic hormone is on the: 
Select and explain. 
A. Distal tubules and collecting ducts in the kidney, B. Afferent arterioles of the glomeruli, C. Thirst center in the hypothalamus, D. Osmoreceptors in the hypothalamus
A: Distal tubules and collecting ducts in the kidney
Answer: A: Distal tubules and collecting ducts in the kidney 
Explanation: None