This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of Thyroid, Subject name: Medicine
Thyrotoxic periodic paralysis leads to extreme muscle weakness due to? 
Select and explain. 
A. Hypokalemia, B. Hypocalcemia, C. Hypomagnesemia, D. Hyponatremia
A: Hypokalemia
Answer: A: Hypokalemia 
Explanation: T3| T4| - Positive Na- K+ ATPase activity in the cells (3 Na outside 2 K+ inside) | K Influx | K| | Thyrotoxic Periodic Paralysis