This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Torsade de pointes is caused by 
Select and explain. 
A. Hypermagnesemia, B. Metabolic acidosis, C. Hypomagnesmia, D. Metabolic alkalosis
C: Hypomagnesmia
Answer: C: Hypomagnesmia 
Explanation: Electrolyte disturbances including hypomagnesmia predispose patients for marked QT prolongation and Torsade de pointes as a result of reduced repolarization reserve Ref Harrison 20th edition pg 1423