Let $E_n=\large\frac{-1me^4}{8\in_0^2 n^2h^2}$ be the energy of the nth level of H- atom . If all the H- atoms are in the ground state and radiation of frequency $(E_2-E_1) /h$ falls on it ,

Question

$\begin{array}{1 1} \text{it will not be absorbed at all } \\ \text{Some of atoms will move to the first excited state.} \\ \text{all atoms will be excited to the n=2 state } \\ \text{none of the above} \end{array} $