From what age may one vote in local elections in Rhineland-Palatinate?

EDITORIAL LEARNING AID

Why is this answer correct?

In Rhineland-Palatinate the voting age for local elections is 18; there is no reduction to 16 there, unlike in North Rhine-Westphalia or Lower Saxony, for example. 14 and 16 are too young, 20 is too high.

Rhineland-Palatinate: local elections only from 18.

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