Which minister does North Rhine-Westphalia not have?

EDITORIAL LEARNING AID

Why is this answer correct?

Foreign policy is the responsibility of the federal government alone (Article 73(1) of the Basic Law), which is why the Federal Foreign Office exists only in Berlin and there is no foreign minister in Düsseldorf. Justice, finance and the interior are separate ministries of the state government.

A foreign ministry exists only at federal level, never in a state.

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