Two wires of the same dimensions but resistivities `rho_(1)` and `rho_(2)` are connected in series. The equivalent resistivity of the combination is
A. `(rho_(1)+rho_(2))/(2)`
B. `rho_(1)+rho_(2)`
C. `(rho_(1)rho_(2))/(rho_(1)+rho_(2))`
D. `sqrt(rho_(1)rho_(2))`