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: Unknown
[{'content': 'Which treatment would be least effective for asystole? \nSelect and explain. \nA. External pacemaker, B. Intravenous epinephrine, 10 ml. of 1:10,000., C. Intravenous calcium gluconate, 10 ml. of 10% solution, D. Intravenous atropine, 0.5 mg.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Recommended treatment for asystole is administration of atropine. If atropine is unsuccessful epinephrine is given. Ultimately cardiac pacing is necessary if atropine and epinephrine do not establish an adequate heart rate. Calcium has no clear role in treating asystole.', 'role': 'assistant'}]