What are the two AOCs within Bordeaux associated with very good to outstanding quality dry Sauvignon Blanc based wines?

The two AOCs within Bordeaux known for producing very good to outstanding quality dry Sauvignon Blanc wines are Graves AOC and Pessac-Léognan AOC.

Graves AOC, which encompasses a range of wine styles, is particularly recognized for its excellent Sauvignon Blanc as well as the notable blends with Sémillon. The unique gravelly soils of the region promote good drainage and contribute to the complexity and character of the wines.

Pessac-Léognan AOC is a subregion of Graves and is renowned for its high-quality white and red wines, with a strong emphasis on Sauvignon Blanc. The terroir here is highly regarded, and the wines often exhibit vibrant acidity and intense flavor profiles, showcasing the grape's full potential.

The other choices either include AOCs that do not specialize in dry Sauvignon Blanc (like Sauternes, which is primarily known for sweet wines) or AOCs that aren't recognized for quality dry white wine production reflective of Sauvignon Blanc's characteristics.