Which of the following criteria could NOT be used for a Dynamic Remarketing audience?
Users who viewed your homepage
Users who viewed a search result page on your website
Users who viewed product detail pages
Users who returned an item they purchased
you can implement Dynamic Remarketing by using the preconfigured All Users list, creating more narrowly targeted lists lets you focus your ad content and budget where it will have the most impact. For example, users who have already added items to their shopping carts might need just a reminder or incentive to complete their transactions, while users who have only viewed the products may need more convincing about the overall value of the products.
By following the same procedure you use to create Remarketing Audiences, you can build segment-based Dynamic Remarketing Audiences using your new dimensions.
Read more here: https://support.google.com/analytics/answer/3457161