How did the Federal Republic of Germany and the GDR become one state?

EDITORIAL LEARNING AID

Why is this answer correct?

For the “Leben in Deutschland” test, connect “Today's five eastern federal states acceded to the Federal Republic of Germany.” with the meaning of the question. This is the answer marked as correct in the official key. “The Federal Republic occupied the GDR.” is not part of the solution and points to a different issue. Learn the key term together with the complete correct answer instead of memorising only its letter.

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