An advertiser wants to make sure their AI-driven strategy expansion reaches all relevant users with dynamic messaging. Which pillar of Search Excellence addresses this?

This is the targeting and creatives pillar. The question describes two things together: reaching all relevant users, which is a targeting job handled by broad match and AI Max expansion, and dynamic messaging, which is a creative job handled by responsive search ads, asset variety and features such as text customization. Search Excellence pairs them in a single pillar deliberately, because expansion without adaptive creative is wasted. If the AI matches an ad to a query the advertiser never listed, the ad copy has to be able to speak to that query, or the extra reach converts poorly. The reverse is equally true: rich, flexible assets cannot help if targeting keeps the campaign inside a narrow keyword list. Providing broad, high-quality assets and letting matching expand is how this pillar is implemented in practice.