This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Sodium and Potassium, Subject name: Pediatrics
Most common cause of hyponatremia in children is? 
Select and explain. 
A. Excessive sweating, B. Vomiting, C. Syndrome of inappropriate ADH, D. Diuretic use
C: Syndrome of inappropriate ADH
Answer: C: Syndrome of inappropriate ADH 
Explanation: Most common cause of hyponatremia in children - Syndrome of inappropriate ADH.