Which destination requires enabling ID sync functionality to target a segment of non-authenticated website cart abandoners?

The correct choice is related to the need for ID sync functionality because of how data integrations are set up in different advertising platforms. Specifically, Google DV360 (Display & Video 360) is an integrated platform that leverages user IDs to optimize targeting and remarketing efforts.

To successfully target segments such as non-authenticated website cart abandoners, it's essential to have ID sync enabled. This allows you to create a more comprehensive view of user interactions across different platforms and devices, facilitating more effective audience targeting and campaign performance. Unlike other options listed, Google DV360 specifically requires this feature to connect and effectively reach users who have shown intent through their actions on the website, even if they are not logged in or authenticated. This makes it crucial for remarketing strategies to enable ID sync for such targeting efforts, allowing you to engage users who have left items in their cart without completing a purchase.

Thus, selecting Google DV360 as the answer reflects an understanding of the technical requirements for effective audience segmentation in digital advertising through the Adobe Real-Time Customer Data Platform.