De-Broglie hypothesized that material particles have wave like properties. Figure shows a small particle in a box. The particle simply bounces back and forth at constant speed. As particles also have wave like properties it can be considered to be a wave reflecting back and forth from the ends of the box. The reflections will create a standing wave analogous to standing wave on a string tied at both ends. Since a standing wave confined to a region can have only selected wavelength, momentum of the particle is quantized. We can safely assume that such a particle only has kinetic energy. This energy must also be quantized. Bohr model is applied to signly ionized helium `He^(+)` Consider the lines that lie in the visible region of the spectrum. Which of the following transitions can given a photon of visible light?A. `n=5` to `n=4`B. `n=7` to `n=4`C. `n=4` to `n=3`D. `n=8` to `n=3`