心肌工作细胞静息电位形成的主要原因是( )

A、K[img=~\/QImg\/2013-06-27-14-49-35\/image001.gif]外流
B、Na[img=~\/QImg\/2013-06-27-14-49-35\/image001.gif]内流
C、Na[img=~\/QImg\/2013-06-27-14-49-35\/image001.gif]-K[img=~\/QImg\/2013-06-27-14-49-35\/image001.gif]泵生电作用
D、Cl[img=~\/QImg\/2013-06-27-14-49-35\/image002.gif]内流
E、Ca[img=~\/QImg\/2013-06-27-14-49-35\/image006.gif]内流