This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hypeension, Arrhythmias, Dyslipidemia, Subject name: Pharmacology
[{'content': 'Beta-blockers are used in all of the following except:- \nSelect and explain. \nA. Essential tremors, B. AV block, C. Angina pectoris, D. Migraine prophylaxis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In AV block, HR is 40 bpm and b blockers fuher causes cardiac depression. Therefore they are avoided in this condition. In all other 3 conditions, b blockers are used.', 'role': 'assistant'}]