This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following is most useful for reversing severe ergot induced vasopam \nSelect and explain. \nA. Ergotamine, B. Methysergide, C. Nitroprusside, D. Phenoxybenzamine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: this agent is mixed dilator and is Highly Effective agent against ergot induced vasospasm. it is also the drug of choice for most of the hypeensive emergencies Ref-Goodman and Gillman 11/e p311', 'role': 'assistant'}]