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 $\lambda_1$, $\lambda_2$ and $\lambda_3$ are wavelengths of radiations corresponding to transitions $C \to B$, $B \to A$ and $C \to A$ respectively, which of the following relations is correct?