The follwing diagram indicates the energy levels of a certain atom when the system moves from `2E` level to `E`, a photon of wavelength `lambda` is emitted. The wavelength of photon produced during its transition from `(4E)/(3)` level to `E` is
A. `lambda//3`
B. `3lambda//4`
C. `4lambda//3`
D. `3lambda`