A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference $V$ esu. If $e$ and $m$ are charge and mass of an electron, respectively, then the value of $h/ \lambda$ (where $\lambda$ is wavelength associated with electron wave) is given by :

Question

( A ) $meV$
( B ) $2 meV$
( C ) $\sqrt{2 meV}$
( D ) $\sqrt{ meV}$