3 I don’t know but it may be movement
I believe it’s A..but I’m not quite sure.
In order to conduct the two-slit experiment with a beam of electrons, the slit opening has to be smaller than the opening for the light waves. This is because the wavelength of the electron beam is lower, which means it will pass through the large slit without diffracting. Diffraction will occur if the spacing is reduced. The reason that electrons have a smaller wavelength is because they have a higher energy than light waves.
C: plates slipping along a fault