Which of the following is a common mixer used in cocktails?

Soda is commonly used as a mixer in cocktails due to its effervescence and ability to add sweetness or a refreshing flavor. It acts as a versatile ingredient that enhances the base spirit without overpowering it. For instance, soda can be paired with various liquors like whiskey, rum, or vodka to create popular mixed drinks such as whiskey soda or vodka soda. Its carbonated nature also helps in balancing flavors and providing a light, bubbly texture that many people enjoy in cocktails.

While whiskey, beer, and vodka are all base spirits on their own, they are typically used as primary ingredients rather than mixers. This is why soda is recognized as a key component in mixology.