A system is represented by the block diagram shown below.

Which one of the following represents the input-output relationship of the above diagram?
(a) \(\mathrm{R}(s) \longrightarrow \mathrm{G}_{1} \mathrm{G}_{2} \longrightarrow \mathrm{C}(s)\)
(c) \(\mathrm{R}(s) \longrightarrow 1+\mathrm{G}_{1}+\mathrm{G}_{1} \mathrm{G}_{2} \longrightarrow \mathrm{C}(s)\)
(b) \(\mathrm{R}(s) \longrightarrow \mathrm{G}_{1}+\mathrm{G}_{2} \longrightarrow \mathrm{C}(s)\)
(d) \(\mathrm{R}(s) \longrightarrow 1+\mathrm{G}_{2}+\mathrm{G}_{1} \mathrm{G}_{2} \longrightarrow \mathrm{C}(s)\)

R(s) G G -C(s)