In the "Rusty Nail," what type of whisky is traditionally used?

The "Rusty Nail" is a classic cocktail that combines Scotch whisky and Drambuie, a Scotch-based liqueur flavored with honey and herbs. The choice of Scotch whisky is essential because it provides the foundational flavor profile that distinguishes this cocktail. Scotch is known for its unique characteristics, which can range from smoky and peaty to smooth and fruity, depending on the brand and region it comes from. These flavors are complemented by the sweet and herbal notes of Drambuie, creating a balanced drink.

Using other types of whisky, such as Bourbon or Irish whiskey, would alter the drink's intended flavor profile significantly, as they have distinct flavor characteristics that do not match the traditional essence of a "Rusty Nail." American whiskey, while versatile, would also not provide the same depth and complexity that Scotch brings to the cocktail. Therefore, the use of Scotch whisky is a hallmark of the "Rusty Nail," making it the correct answer.