如下图所示，闭环离散系统的输出C(z)=

12.png

A、
(GR(z))/(1+GH(z))

B、
(G(z)R(z))/(1+GH(z))

C、
(GR(z))/(1+G（z）H(z))

D、
(G（z）R(z))/(1+G（z）H(z))