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: Medicine
Torsade-de-pointes is caused by - 
Select and explain. 
A. Hypermagnesemia, B. Metabolic acidosis, C. Hypomagnesemia, D. Metabolic alkalosis
C: Hypomagnesemia
Answer: C: Hypomagnesemia 
Explanation: None