Which famous US winemaker is known for founding Vina Cobos in Argentina?

The correct choice is Paul Hobbs, who is renowned for founding Vina Cobos, a winery located in Mendoza, Argentina. Hobbs has played a significant role in the global wine industry, not just in the United States but also in Argentina, where he has helped to cultivate a reputation for high-quality wines. His approach typically emphasizes hand-harvesting, careful vineyard management, and a focus on expressing the unique terroir of the regions he works in. This commitment has led Vina Cobos to become well-respected for its premium Malbec and other varietals, contributing significantly to the reputation of Argentine wines on the international stage.

The other names mentioned are notable in the wine world for various reasons, but they are not directly associated with the founding of Vina Cobos. Mark Oldman is known more for his writing and education about wine rather than winemaking. Fred Franzia is known for the successful brands he has built, primarily in California, and Robert Parker is a prominent wine critic whose ratings have influenced wine sales. None of these figures have founded a winery in Argentina like Paul Hobbs did with Vina Cobos.