What colours does the state flag of Saxony have?

EDITORIAL LEARNING AID

Why is this answer correct?

The state flag of Saxony is white and green; the colours are derived from the Saxon coat of arms. Blue-white-red is the flag of Schleswig-Holstein, black-yellow that of Saxony-Anhalt, and green-white-red are the colours of North Rhine-Westphalia.

White and green like the rue crown in the coat of arms: Saxony.

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