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: Medicine
[{'content': 'Drug used in AV Block  a)  Isoprenaline  b)  Dopamine  c) Astropine  d) Disopyramide  e)  Propranolol \nSelect and explain. \nA. ac, B. ad, C. bd, D. cd', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]