What colours does the state flag of Thuringia have?

EDITORIAL LEARNING AID

Why is this answer correct?

The state flag of Thuringia has white and red stripes. Blue-white-red is the flag of Schleswig-Holstein, black-gold that of Baden-Württemberg, and green-white-red are the colours of North Rhine-Westphalia.

White-red, short and simple: Thuringia.

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