Explanation

(c)
First of all, de-Broglie told that like light, all the microscopic moving particles also have dual nature, $i.e$., both wave and particle nature. Hence, for any microscopic particle (like $e^{-},p^{+}n\$etc) the wavelength is given by
$\lambda = \frac{h}{mv} = \frac{h}{p}$
where, $h$=Planck’s constant
$mv$=$p$=momentum