Who elects the Federal President in Germany?

EDITORIAL LEARNING AID

Why is this answer correct?

The Federal Assembly elects the head of state; it consists of the members of the Bundestag and an equal number of members elected by the state parliaments (Art. 54 GG). The Bundesrat (b), the Federal Parliament (c, not a separate constitutional body) and the Federal Constitutional Court (d) do not elect the President.

Only the Federal Assembly elects the Federal President.

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