Which wine is generally considered to be sweeter?

Riesling is generally considered to be sweeter than the other wines listed. This aromatic white grape variety is known for producing wines that range from dry to very sweet, often showcasing a high level of residual sugar. The sweetness in Riesling can be attributed to the grape's natural acidity and its ability to maintain sugar levels even after fermentation.

In contrast, Cabernet Sauvignon, Sauvignon Blanc, and Merlot typically produce drier wines, with a focus on their respective flavor profiles such as dark fruits in Cabernet and lighter, citrus or herbal notes in Sauvignon Blanc. While some versions of Merlot can present subtle fruitiness, they usually do not elevate to the sweetness levels found in wines made from Riesling grapes. Thus, Riesling stands out for its characteristic sweetness, making it the correct choice among the options provided.