Two charges 2 C and 6C are separated by a finite distance. If a charge of $-4C$ is added to each of them, the initial force of $12 \times 10^3\;N$ will change to :

Question

$$\begin {array} {1 1} (a)\;4 \times 10^3 N(repulsion) & \quad (b)\;4 \times 10^2 N(repulsion) \\ (c)\;6 \times 10^3 N(attraction) & \quad (d)\;4 \times 10^3 N(attraction) \end {array}$$