Which of the following grape varieties is NOT traditionally grown in the southern Rhone?

Cabernet Sauvignon is the grape variety that is not traditionally grown in the southern Rhône region. The southern Rhône is known for its unique blend of grape varieties that thrive in its warm Mediterranean climate and distinct terroir.

Cinsault, Mourvèdre, and Grenache are quintessential varieties of this region. Grenache is particularly dominant and forms the backbone of many red blends, while Mourvèdre and Cinsault complement it within these blends. Cabernet Sauvignon, while it is a globally popular variety and has been planted in various regions around the world, is more commonly associated with Bordeaux and other areas with a different climate and soil profile. Therefore, it does not have a traditional or significant presence in the southern Rhône, making it the correct answer.