John is running a test campaign with CTR as the main KPI. He is trafficking five ads per placement and wants to make sure the best performing ads are displayed more often to end users. Which setup is best suitable to John’s goal?

Monitor data and use creative refresh to replace the underperforming ads
Create a delivery group with five ads and select “automatic optimization based on CTR” as the rotation method
Monitor performance and manually increase delivery group weights in favor of the best performing ads
Add five delivery groups to the same placement and detach the underperforming ones