This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Body fluid compaments, Subject name: Physiology
Which of the following is cause of Hyperkalemia: 
Select and explain. 
A. Exercise, B. Alkalosis, C. Insulin injection, D. Decrease serum osmolarity
A: Exercise
Answer: A: Exercise 
Explanation: Exercise causes hyperkalemia because Na+-K+ pump cannot keep pace with the K+ efflux from muscle during the depolarization-repolarization process of the sarcolemmal membrane during muscle contraction. Causes of shift of K+ out of cells i.e. Hyperkalemia: Insulin deficiency Beta adrenergic antagonist Acidosis Hyperosmolarity Inhibitors of Sodium potassium ATPase pump Exercise Cell lysis Causes of shift of K+ into cells i.e. Hypokalemia: Insulin Beta adrenergic agonist Alkalosis Hypoosmolarity