What does "popular sovereignty" mean? All state power emanates from the …

EDITORIAL LEARNING AID

Why is this answer correct?

Popular sovereignty means that all state authority derives from the people (Art. 20(2) GG). The Bundestag (b) is itself an organ of the people, the Prussian king (c) stands for the monarchy that was overcome, and the Federal Constitutional Court (d) reviews state authority but is not its source.

Art. 20(2) GG: all state authority emanates from the people.

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