Which of the following categories of Scotch involves a blend of one or more single grain and one or more single malt scotches?

Blended Scotch refers to a category that combines both single malt and single grain scotch whiskies. In this classification, single malts are produced from malted barley at a single distillery, while single grain whiskies can include any grain and may come from one or multiple distilleries. The blending of these two types creates a more complex and balanced flavor profile, appealing to a wider audience than single malts alone.

The other categories listed differ in that single malt refers exclusively to whisky from a single distillery made from 100% malted barley, while blended grain involves mixing multiple single grain whiskies. Blended malt is characterized by a combination of single malt whiskies from various distilleries, entirely excluding grain whiskies. Therefore, the combination of single grain and single malt whiskies in blended Scotch is what distinctly defines this category.