From what age may one vote in Bremen in elections to the Bürgerschaft (state parliament)?

EDITORIAL LEARNING AID

Why is this answer correct?

In Bremen people have been allowed to vote for the Bürgerschaft from the age of 16 since 2011. At 14 one is too young, 18 is the general voting age for Bundestag elections, and 20 would be too high.

In Bremen the rule for Bürgerschaft elections is: vote from 16.

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