<prompt> Plateau phase of cardiac cycle is due to -NaKCa2Cl-  <response>: Ans. is c i.e., Ca2 o Phase 0 phase of rapid depolarization- opening of fast sodium channels with Na4 influxo Phase 1 initial phase of rapid repolarization- closure of fast sodium channelso Phase 2 plateu phase- opening of voltage gated slow Ca channels with calcium influx.o Phase 3 final repolarization- opening of K channels with K efflux.o Phase 4- Resting membrane potential. 