After a heart contraction, all of the following play a role in reducing the cytoplasmic Ca2+ concentration EXCEPT:(A) Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA)(B) Plasma membrane Na+/Ca2+ exchanger(C) Plasma membrane Ca2+ ATPase(D) Sarcoplasmic/endoplasmic reticulum Na+/Ca2+ exchanger Checking your answer...