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: Pharmacology
Carbamazepine in elderly causes : 
Select and explain. 
A. Hypernatremia, B. Hyponatremia, C. Hyperkalemia, D. Hypokalemia
B: Hyponatremia
Answer: B: Hyponatremia 
Explanation: None