- A feed
- The creative code
- Dynamic rules
- Custom Floodlight variables
The correct answer is: Custom Floodlight variables
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.
Read more here:https://support.google.com/richmedia/answer/7412608
Explanation: Echo remarketing is an advertising strategy that connects a user’s actions on a site back to a dynamic creative.
Read more here:https://support.google.com/richmedia/answer/6277637