You’d like to add mobile ads to your current campaign, but some creatives are already mobile-optimized and could be appearing on mobile websites. What’s the first consideration you should look at within the Campaign Manager 360 account to make sure of delivery and to reach your goal?

Review your Cross-environment Report to check on campaign effectiveness across all environments, including mobile.
Configure your account within Campaign Manager 360 to include apps, mobile devices, and tablets.
Use mobile-friendly sizes and formats when organizing your campaign in Campaign Manager 360.
Examine your trafficking settings in Campaign Manager 360 to determine if mobile-friendly sizes and formats are included.