Which of the following is a common white grape varietal used in wine production?

Sauvignon Blanc is a well-known white grape varietal that is extensively used in wine production around the world. This grape is characterized by its high acidity and aromatic qualities, which often include green apple, lime, passion fruit, and occasionally herbaceous notes like bell pepper and freshly cut grass. It is primarily grown in regions such as Bordeaux and the Loire Valley in France, as well as in New Zealand and California, where it can produce a wide range of wine styles, from crisp and refreshing to more complex, barrel-aged versions.

In contrast, the other grape varietals listed are primarily associated with red wine production. Merlot and Cabernet Franc are both red grapes commonly used in Bordeaux-style blends, while Pinot Noir is another red grape known for its role in the production of light-bodied red wines, particularly in Burgundy, as well as sparkling wines like Champagne. Therefore, Sauvignon Blanc stands out as the correct answer for a common white grape varietal in the context of the question.