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
[{'content': 'Torsade de pointes is caused by \nSelect and explain. \nA. Hypermagnesemia, B. Metabolic acidosis, C. Hypomagnesmia, D. Metabolic alkalosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 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', 'role': 'assistant'}]