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
Cornerstone of therapy for chronic hyponatremia is which of the following intervention? 
Select and explain. 
A. Vasopressin antagonists, B. Hypeonic 3% saline, C. Water deprivation, D. Demeclocycline
C: Water deprivation
Answer: C: Water deprivation 
Explanation: Water deprivation has long been a cornerstone of therapy for chronic hyponatremia. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 347