d
(d) \(2E - E = \frac{{hc}}{\lambda } \Rightarrow E = \frac{{hc}}{\lambda }\)

\(\frac{{4E}}{3} - E = \frac{{hc}}{{\lambda '}} \Rightarrow \frac{E}{3} = \frac{{hc}}{{\lambda '}}\;\;\therefore \frac{{\lambda '}}{\lambda } = 3 \Rightarrow \lambda ' = 3\lambda \)