Explanation

(c)
de-Broglie, first of all suggested that electron, like light photons, possess wave nature. He proposed that all micro-particles have dual nature $i.e$., both wave nature and particle nature. The wavelength of electron is given by
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \lambda = \frac{h}{mv}$
where, $h =$Planck’s constant