Which is a common garnish for a gin and tonic?

A lime wedge is a common garnish for a gin and tonic because it enhances the drink's flavor profile by adding a fresh, zesty acidity that complements the botanicals found in the gin and the crispness of the tonic water. The citrus notes of lime elevate the overall drinking experience, making it more refreshing and balanced. This practice is widely recognized in bars and is a classic pairing that many patrons expect when ordering a gin and tonic, showcasing the drink's refreshing characteristics.