- Floodlight custom variable (“u-var”) values
- Third-party cookie values
- The advertiser’s cookie values
- Floodlight audience list IDs
The correct answer is: Floodlight audience list IDs
Explanation: Before you can begin to build your dynamic creative, you first need to add Floodlight tags to the web pages where you want to track user activity. The Floodlight tags must be created in the same Campaign Manager account where you’ll push your dynamic creatives. Each Floodlight tag should include custom variables that you’ll use to pass remarketing data to your creatives.A Floodlight tag can have up to 100 custom variables (also referred to as u-variables). However, we recommend only using 1 or 2 custom variables in your dynamic strategy.
Read more here:https://support.google.com/richmedia/answer/7412608