An agency is building a mobile ad campaign with their client who wants their ads to serve to a current-generation browser.To meet their goal, which ad inventory option should they use?

To serve ads to a current-generation browser, the agency should target web inventory. Smartphone and desktop web ads are displayed within a browser environment, which directly addresses the client's requirement. Smartphone and tablet ads (without specifying "web") could include in-app inventory, which doesn't necessarily use a browser. Mobile in-app ads are served within applications, not browsers. Out-stream and in-stream video ads refer to video ad formats and placements, not the underlying inventory type (browser vs. app) that the client is focused on.