Calculate the effective address of the following instructions if register R$3=0$x$4000$ and register R$4=0$x$20$: LDR R$7,[$R$3],$ R$4$ A$.$Effective Address$=0$X$4000$ B$.$Effective Address$=0$XCDAE $$c$.$Effective Address$=0$X$3000$d$.$Effective Address$=0$X$40$CD