For the signal flow graph shown in the figure, determine the overall transmittance relating C and R.
1
\(\frac{G_{1}+G_{2}}{1−G_{1}H_{1}+G_{2}H_{1}}\)
2
\(\frac{G_{1}+G_{2}}{1+G_{1}H_{1}−G_{2}H_{1}}\)
3
\(\frac{G_{1}+G_{2}}{1+G_{1}H_{1}+G_{2}H_{1}}\)
4
\(\frac{G_{1}G_{2}}{1+G_{1}H_{1}+G_{2}H_{1}}\)