A photoelectric surface is illuminated successively by monochromatic light of wavelengths $λ$ and $\frac{λ}{2}$. If the maximum kinetic energy of the emitted photoelectrons in the second case is $3\; times$ that in the first case, the work function of the surface is :

Question

$\begin{array}{1 1}(1) \frac{hc}{3 \lambda} \\ (2) \frac{hc}{2 \lambda} \\ (3) \frac{hc}{\lambda} \\ (4) \frac{3 \lambda hc}{\lambda} \end{array}$