Which of the following is classified as a dark spirit?

The classification of spirits into categories like 'dark' and 'light' often pertains to their color, production processes, and aging. Scotch is a type of whisky that is typically aged in wooden casks, which imparts a darker color to the liquor, as well as distinctive flavors associated with the aging process.

Dark spirits, such as Scotch, possess a rich complexity that comes from their maturation in barrels, which can previously hold sherry, bourbon, or other liquors. This aging process contributes to their depth of flavor and darker appearance, differentiating them from lighter spirits.

On the other hand, tequila, gin, and rum can be classified differently based on their characteristics. For example, tequila can be clear or golden depending on its aging, gin is usually a clear spirit, and while some rums can be dark, they are not universally classified as dark spirits like Scotch is. Thus, Scotch stands out as the definitive dark spirit among the choices provided.