This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'All of the following drugs reduce afterload ,except \nSelect and explain. \nA. Enalapril, B. Propranolol, C. Hydralizine, D. Sodium nitroprusside', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Afterload is reduced by the drugs having aeriolar dialting propey. Propranolol is a non selective beta blockers. It can cause Vasoconstriction by antagonizing beta 2 mediated vasodilatation. It, therfore do not cause afterload Refer kDT 6/e 504', 'role': 'assistant'}]