This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'Cardioselective beta blockers is contraindicated in \nSelect and explain. \nA. COPD, B. II & III degree heart block, C. Asthma, D. Tachycardia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (B) II & III degree heart block# Except for those drugs specifically approved for use in heart failure, beta blockers are contraindicated in heart failure patients> Side effects of beta-blockers are related to their cardiac mechanisms and include bradycardia, reduced exercise capacity, heart failure, hypotension, and atrioventicular (AV) nodal conduction block.> Beta-blockers are therefore contraindicated in patients with sinus bradycardia and partial AV block.> Non-selective beta-blockers are contraindicated in patients with asthma or chronic obstructive pulmonary disease which is not a contraindication for cardioselective beta blockers.', 'role': 'assistant'}]