The equivalent spring stiffness for the system shown in the given Fig. 85 ( S S is the spring stiffness of each of the three

The equivalent spring stiffness for the system shown in the given Fig. 85 ( $S$ is the spring stiffness of each of the three springs) is

(a) $\frac{S}{2}$

(b) $\frac{S}{3}$

(c) $\frac{2S}{2}$

(d) $S$.

S S www m S wwww W Rigid bar Fig.85