Which phenomenon best supports the theory that matter has a wave nature?

$G$ $P$ Thomson experimentally confirmed the existence of matter waves by the phenomenon of:

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement-$1$: Davisson-Germer experiment established the wave nature of electrons.
Statement-$2$: If electrons have wave nature,they can interfere and show diffraction.

In the Davisson-Germer experiment,for which value of accelerating voltage was the intensity of the electron beam found to be maximum (in $V$)?

In the Davisson-Germer experiment,an electron beam of energy $75 \ eV$ falls normally on the surface of a crystal. If the maximum intensity is obtained at an angle of $45^o$ to the direction of the incident beam,then the inter-atomic distance in the lattice plane of the crystal will be .............. $\mathring{A}$

State Heisenberg's uncertainty principle.