The block diagram of a feedback control system is shown in the figure. The overall closed-loop gain of $G$ of the system is
- $G = \large\frac{G_1G_2}{1+G_1H_1} \\$
- $G = \large\frac{G_1G_2}{1+G_1G_2+G_1H_1} \\$
- $G = \large\frac{G_1G_2}{1+G_1G_2H_1} \\$
- $G = \large\frac{G_1G_2}{1+G_1G_2+G_1G_2H_1}$