Final answer:
Nero d'Avola is the grape variety used to make full-bodied red wines in Southern Italy, particularly known for its robust and tannic qualities with dark fruit flavors.
Step-by-step explanation:
The grape variety used to make full-bodied red wines in Southern Italy is d) Nero d'Avola. This variety is native to Sicily and is known for producing robust, tannic wines with rich flavors of dark fruits. Unlike other popular grape varieties like Merlot, Cabernet Sauvignon, and Syrah/Shiraz, Nero d'Avola is distinctly Sicilian and has become synonymous with the bold, hearty reds from the region.