This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Drug not used in Prinzmetal angina is: \nSelect and explain. \nA. Propranolol, B. Verapamil, C. Nitrites, D. Isosorbide dinitrate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Propranolol', 'role': 'assistant'}]