Aprocess that modifies light waves so they viberate in a single plane is refered to as

The question is fishing for "polarization", but the description is all wrong.

Polarization doesn't do anything to the light waves.
It simply blocks any light waves that are not vibrating in
the desired plane, and lets the leftovers pass through.

If there are no light waves already vibrating in the desired plane
in the light that enters the polarizer, then NO LIGHT comes out of it.

If you line up two polarizers and rotate them so that their desired
planes are crossed, then regardless of what goes into the first one,
NO light comes out of the second one !