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
Vasopressin acts bya) Water transport across collecting ductb) Water absorption at medullary ductsc) Water secretion at loop of Henled) Water transport at PCT 
Select and explain. 
A. ab, B. a, C. ad, D. bc
A: ab
Answer: A: ab 
Explanation: Angiotensin II acts on 

PCT
Thick ascending limb of loop of Henle
DCT
Collecting duct

 Aldosterone acts on

Late DCT
Collecting duct

 ADH acts on

DCT
Collecting duct

 ANP acts on

DCT
Collecting duct