When it comes to mobile in-app and mobile web inventory in Display & Video 360, what statement is true?

Marketplace in Display & Video 360 allows advertisers to discover and negotiate deals for premium inventory across various channels, including both mobile web and mobile in-app environments. Publishers list their inventory, and advertisers can browse, filter, and request proposals for guaranteed or preferred deals, ensuring access to high-quality placements regardless of whether they are in a mobile browser or within an application. The other options are incorrect because: app-ads.txt is specifically for mobile in-app inventory, not mobile web, to combat ad fraud. Creative dimensions are applied based on the specific ad unit and format, not universally across both mobile web and in-app inventory as a single setting. App collections are used to target or exclude specific mobile applications, which is relevant for in-app inventory, but not for mobile web inventory.