This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'Which of the following agent is a class c antiarrhythmic drug \nSelect and explain. \nA. Quinine, B. Amiodarone, C. Propranolol, D. Lignocaine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer kDT 7/e 529 Class III agents have the potential to prolong the QT interval of the EKG, and may be proarrhythmic (more associated with development of polymorphic VT). Class III agents include: bretylium, amiodarone, ibutilide, sotalol, dofetilide, vernakalant and dronedarone', 'role': 'assistant'}]