Which region in Argentina is known for its diverse grape varieties due to a more temperate climate?

Mendoza is recognized for its diverse range of grape varieties, primarily attributed to its more temperate climate, which allows for a broader cultivation of different types of grapes. As Argentina's largest wine-producing region, Mendoza benefits from a wide range of altitudes and microclimates, thanks to the Andes Mountains that provide both irrigation from snowmelt and protection from harsh weather. This diversity in climate leads to the successful growing of various grape varieties, including Malbec, Cabernet Sauvignon, and Torrontés, making Mendoza a dynamic and versatile region for wine production.

Cafayate, though significant for its Torrontés, is more specialized. San Juan, while known for its warmer climate overall and larger production volume, does not match Mendoza in terms of grape variety diversity. Rio Negro, in Patagonia, has a cooler climate conducive to specific types of grapes but does not have the same recognized diversity as Mendoza. Therefore, Mendoza stands out as the correct region associated with a wider array of grape varieties due to its temperate climate.