Energy levels A, B and C of a certain atom correspond to increasing values of energy i.e. ${E_A}<{E_B}<{E_C}$ . If${\lambda_1},{\lambda_2},{\lambda_3}$ are wave lengths of radiations corresponding to transitions C to B, B to A and C to A respectively, which of the following relations is correct -

Question

( A ) $\lambda_1+\lambda_2+\lambda_3=0$
( B ) $\lambda{_3}{^2}=\lambda{_1}{^2}+\lambda{_2}{^2}$
( C ) $\lambda_3=\lambda_1+\lambda_2$
( D ) $\lambda_3=\frac{\lambda_1\lambda_2}{\lambda_1+\lambda_2}$