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: Surgery
All electrolyte abnormalities are seen in immediate postoperative period, EXCEPT - 
Select and explain. 
A. Negative Nitrogen balance, B. Hypokalemia, C. Glucose intolerance, D. Hyponatremia
D: Hyponatremia
Answer: D: Hyponatremia 
Explanation: Following surgery there is variable period of reduced excretion of sodium due to increased adrenocortical activity. This leads to hypernatremia therefore it is advisable not to administer large quantities of isotonic (a) saline solution.
Sometimes postoperative hyponatremia too develops, as a result of too prolonged administration of sodium free solution.