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: Pharmacology
[{'content': 'Fellypressin is a \nSelect and explain. \nA. Vaso dilator, B. Vaso constrictor, C. Neuroleptic drug, D. Anti coagulant', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]