Copper and carbon wires are connected in series and the combined resister is kept at $0^{\circ} C$. Assuming the combined resistance does not vary with temperature, the ratio of the resistances of carbon and copper wires at $0^{\circ}C$ is ( Temperature coefficients of resistivity of copper and carbon respectively are $4 \times 10^{-3} / ^{\circ}C\: and \: -0.5 \times 10^{-3}/^{\circ}C$)

Question

$\begin {array} {1 1} (1)\;4 & \quad (2)\;8 \\ (3)\;6 & \quad (4)\;2 \end {array}$