Correct Answer: C, DTo change the layout of a specific web page in a public-facing Power Apps portal, you can use the portal app directly or manage it through editing options. Firstly, by selecting the portal app and then selecting 'Manage,' you can access settings that allow for the configuration of various elements including web page layouts. Secondly, selecting the portal app and then clicking 'Edit' will enable you to make specific changes to the web page content and structure within the Power Apps portal environment. Option A involves editing the Portal Management app itself, which is not intended to directly modify the layout of a specific web page within the portal. Option B, for 'Play,' means running the application, which would not allow for any edits to be made. Therefore, the correct approaches are using 'Manage' or 'Edit' within the portal app.