This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Which of the following is the least useful drug for the use in Congestive cardiac failure? \nSelect and explain. \nA. Bucindolol, B. Pimobenden, C. Vesnarinone, D. Trimetazidine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Trimetazidine is a novel antianginal drug which acts by nonhemodynamic mechanisms.', 'role': 'assistant'}]