Was ist das Kleinste und Westlichste Bundesland Österreichs?

Why this is the correct answer

Vorarlberg is Austria's westernmost and second-smallest state by area, nestled between Switzerland, Liechtenstein, Germany, and Tyrol. Despite its compact size, it has a strong economy and a distinct cultural identity shaped by its Alemannic heritage and close ties to the German-speaking Swiss and German regions next door.