Which two grape varieties is Zweigelt a cross between?

Zweigelt is indeed a cross between Blaufränkisch and St. Laurent. This grape variety was created in Austria by Dr. Friedrich Zweigelt in the 1920s. The resulting varietal combines characteristics of both parent grapes, offering a profile that is typically fruity and spicy, with moderate acidity and tannins.

Blaufränkisch is known for its dark fruit flavors and structured tannins, while St. Laurent contributes elegance, with its berry-like fruit and higher acidity. The fusion of these traits in Zweigelt results in a versatile wine that is often enjoyed both young and with some age, showcasing the strengths of its parent varieties.

The other grape combinations listed involve different varietals that do not contribute to the lineage of Zweigelt, thereby confirming that option C is the only accurate choice.