Q: What is required for creative approval?
A) Data sharing is enabled
B) A 3rd-party verification tracker
C) A valid landing page
D) HTML5 formatting
Correct Answer is C) A valid landing page.
Creatives cannot serve until they’re assigned to an active line item and have gone through an initial review that takes approximately 24 hours and includes confirming at least one valid landing page.
Read more here: https://support.google.com/displayvideo/answer/6063030