$\begin{aligned}
& (\mathrm{KE})_{\max }=\frac{\mathrm{hc}}{\lambda}-\phi \
& \frac{\mathrm{hc}}{\lambda} \gt \phi[\text { for emission }] \
& \lambda \lt \frac{\mathrm{hc}}{\phi} \Rightarrow \lambda \lt \frac{1242}{3} \mathrm{~nm}
\end{aligned}$
So blue light option (B)