Name a common ingredient found in a Margarita.

Tequila is the correct answer because it is the primary spirit used in a Margarita. This classic cocktail typically consists of tequila, lime juice, and an orange liqueur such as triple sec or Cointreau. Tequila, made from the blue agave plant primarily in the region surrounding the city of Tequila in Mexico, gives the Margarita its distinctive flavor and character.

The other options listed do not align with the traditional composition of a Margarita. Vodka, whiskey, and gin are all distinct spirits that can be used in different cocktails but are not integral to crafting a Margarita. The use of tequila is what differentiates a Margarita from other mixed drinks, reinforcing its identity and cultural significance in beverage history.