This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
The most powerful feedback system for controlling plasma osmolarity and sodium concentration is 
Select and explain. 
A. ADH and thirst, B. Salt, C. Angiotensin renin system, D. Angiotensin rennin system
A: ADH and thirst
Answer: A: ADH and thirst 
Explanation: If osmotic pressure of the plasma is increased more than normal then the osmoreceptors are activated and ADH secretion increased. There's more receptors causes thirst and increase in the water intake. Daddy secretion causes water retention. This leads to dilution of ECF. Ref: page no 564 Textbook of physiology Volume 1 7th edition AK Jain