The signal flow graph of a feedback control system is given below. The transfer function \(\frac{{C\left( s \right)}}{{R\left( s \right)}}\) of the system is:
1
\(\frac{{{G_1}{G_2} - {G_3}}}{{1 - {G_1}H}}\)
2
\(\frac{{{G_1}{G_2} - {G_3}}}{{1 + {G_1}H}}\)
3
\(\frac{{{G_1}{G_2} + {G_3}}}{{1 + {G_1}H}}\)
4
\(\frac{{{G_1}{G_2} + {G_3}}}{{1 - {G_1}H}}\)