What do the so-called "Stolpersteine" (stumbling stones) in Germany commemorate?

EDITORIAL LEARNING AID

Why is this answer correct?

Stolpersteine are small brass plates set into the ground that commemorate people who were persecuted, murdered or driven out during the Nazi era. They are placed in front of the victims' last freely chosen home and bear their names. They therefore do not commemorate only musicians or politicians and have nothing to do with road deaths.

A brass plate in the ground = the name of a Nazi victim.

This translation and explanation are editorial learning aids. The official German wording and answer key govern the examination.