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': 'Beta blockers are contraindicated in \nSelect and explain. \nA. Angina pectoris, B. Cardiac arrhythmia, C. Cardiac failure, D. Myocardial infarction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]