What is the primary component of a B-52 layered shot?

The primary component of a B-52 layered shot is Kahlua, which is a coffee-flavored liqueur. In the preparation of a B-52, Kahlua serves as the base layer due to its density, allowing for the creation of the signature layered effect. The cocktail is constructed by carefully layering other ingredients above Kahlua, typically Baileys Irish Cream and Grand Marnier. Kahlua's rich coffee flavor complements the other components, making it essential to the overall taste profile of the drink, which is enjoyed not only for its flavor but also for its visual appeal.

The other options, such as whiskey, gin, and tequila, do not belong in the B-52 recipe and do not contribute to the distinct characteristics of this layered shot. Each of these spirits is used in different cocktails, but they would not provide the desired taste or layering effect required for a B-52.