<prompt> Which of the following is a potassium channel opener?NicorandilRanolazineIvabradineNitroprusside  <response>: Ans. A NicorandilRef: Harrison 12th1862Nicorandil is the agent that causes coronary dilation by activating myocardial ATP sensitive K channels. Inaddition it possesses NO releasing property; to which tolerance does not develop. 