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': 'Feature of Torsade de pointes is \nSelect and explain. \nA. Wide QRS complex, B. Sho QRS complex, C. Prolonged QT interval, D. Sho QT interval', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Polymorphic VT that occurs in the context of congenital or acquired prolongation of the QT interval often has a waxing and waning QRS amplitude creat- ing a "twisting about the points" appearance referred to as Torsade de Pointes Ref Harrison 20th edition pg 1443', 'role': 'assistant'}]