Which drink is served straight up with Absolut Citron Vodka?

The drink that is served straight up with Absolut Citron Vodka is Sydney's Cosmo. This cocktail specifically calls for Citron vodka, which is a flavored vodka infused with lemon, offering a refreshing citrus taste that complements the other ingredients typically used in a cosmopolitan, such as cranberry juice and lime juice.

When served "straight up," the drink is chilled before being poured into a glass without ice, which presents it in a refined manner, allowing the vibrant colors and flavors to be highlighted. This preparation method enhances the cocktail's crispness and emphasizes the lemon notes of the Absolut Citron Vodka, making it a popular choice for many guests seeking a sophisticated drink.

The other options refer to different types of beverages that do not include the specific combination of ingredients associated with Sydney's Cosmo or do not involve vodka served straight up.