An electron in a hydrogen like atom makes transition from a state in which itd de Broglie wavelength is `lambda_(1)` to a state where its de Broglie wavelength is `lambda_(2)` then wavelength of photon (`lambda`) generated will be :

A. `lambda=lambda_(1)-lambda_(2)`

B. `lambda=(4mc)/(h){(lambda_(1)^(2)lambda_(2)^(2))/(lambda_(1)^(2)-lambda_(2)^(2))}`

C. `lambda=sqrt((lambda_(1)^(2)lambda_(2)^(2))/(lambda_(1)^(2)-lambda_(2)^(2)))`

D. `lambda=(2mc)/(h){(lambda_(1)^(2)lambda_(2)^(2))/(lambda_(1)^(2)-lambda_(2)^(2))}`