Which of the following is NOT one of the main red grape varieties of the southern Rhone?

Malbec is not one of the main red grape varieties grown in the southern Rhône region. The southern Rhône is particularly known for its blends, with Grenache being the dominant variety, often accompanied by Syrah and Mourvèdre. These three varieties are integral to the production of well-known southern Rhône wines, such as those from the Châteauneuf-du-Pape AOC.

Grenache provides body and fruitiness, Syrah adds color, structure, and spice, while Mourvèdre contributes tannin and complexity. In contrast, Malbec is predominantly associated with the Cahors region in France and is better known for its role in Argentinian wine production, making it less relevant in the context of the southern Rhône's key grape varieties.