This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
[{'content': 'Drug showing additional nitric oxide activity: \nSelect and explain. \nA. Atenolol, B. Metoprolol, C. Bisoprolol, D. Nebivolol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. NebivololAll the drug mentioned are selective beta 1 blockers. Out of all nebivolol has additional nitric oxide activity which increase the level of cGMP and thus causing vasodilation.', 'role': 'assistant'}]