Which of the following grapes is often associated with the Bordeaux AOC?

Cabernet Sauvignon is often associated with the Bordeaux AOC due to its prominent role in many of the region's esteemed wines. Bordeaux is known for its blend of several grape varieties, with Cabernet Sauvignon being a key player, particularly in the left bank of the region, where it thrives in the gravelly soils. This grape is celebrated for producing wines with deep color, full body, and significant aging potential, often characterized by flavors of blackcurrant, cedar, and sometimes hints of green bell pepper when not fully ripe.

In contrast, the other options do not have the same association with Bordeaux. Pinot Noir is primarily linked with regions like Burgundy and Oregon, while Syrah is more synonymous with the Rhône Valley and Australia. Sangiovese is predominantly associated with Tuscany and Italian wines, particularly Chianti. Hence, the strong connection of Cabernet Sauvignon with Bordeaux wines establishes it as the correct answer.