(A) Sign up for the third-party ad networks you want to work with and create a placement in their user interface.
(B) Modify your Ad Manager yield group to add the ad network as a yield partner.
(C) Use the developer guides to implement mediation in your apps.
(D) Pull reports for each yield partner.
This question is a part of the Check your Knowledge section of the “Set Up Ad Manager Mediation” lesson from the “Configure Mobile In-App Ads Using Ad Manager” unit which is part of the Drive Advertising Revenue with Google Ad Manager course.