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': 'What is the alternative for Epinephrine in ACLS? \nSelect and explain. \nA. Low dose dopamine, B. Vasopressin, C. Desmopressin, D. Atropine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. API Textbook of Medicine. Pg. 284\n\xa0\nVasopressin was used as an alternative, but no more used in ACLS\nVasopressin\n\nIn high concentrations, it raises blood pressure by inducing moderate vasoconstriction, and it has been shown to be effective in asystolic cardiac arrest\nVasopressin also is thought to cause cerebral vessel dilation and theoretically increase cerebral perfusion.\nVasopressin may be given IV/IO or by endotracheal tube.\n40 units of vasopressin IV/IO push may be given to replace the first or second dose of epinephrine', 'role': 'assistant'}]