Was ist kein Bundesland der Bundesrepublik Deutschland?Which is not a federal state of the Federal Republic of Germany?

Explanation

Alsace-Lorraine is a French region that belonged to Germany only for certain historical periods and is not one of the current Länder. The other three—Nordrhein-Westfalen, Mecklenburg-Vorpommern, and Sachsen-Anhalt—are established federal states of today’s Germany.