Two particles A and B of the same mass but having charges $q$ and $4q$ respectively, are accelerated from rest through different potential differences $V_A$ and $V_B$ such that they attain same kinetic energies. The value of $\left(\frac{V_A}{V_B}\right)$ is : (A) $\frac{1}{4}$ (B) $\frac{1}{2}$ (C) $2$ (D) $4$