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': 'Mechanism of action of levosimendan include: \nSelect and explain. \nA. Na channel opener, B. K channel opener, C. Beta blocker, D. Beta 1 agonist', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B) K channel opener(Ref: Katzung 11th/e p.221)Levosimendan is an inodilator that act by[?]Ca2+ sensitizing action by binding to troponin-C (inotropic action)[?]K+ Channel opening action -- (responsible for vasodilation)', 'role': 'assistant'}]