(c)
The de-Broglie wavelength associated with the charged particle as
For electron, $\lambda = \frac{12.27}{\sqrt{V}}\mathring{\mathrm{A}}$
For proton, $\lambda = \frac{0.286}{\sqrt{V}}\mathring{\mathrm{A}}$
For $\alpha$-particles, $\lambda = \frac{0.101}{\sqrt{V}}\mathring{\mathrm{A}}\$