You have a SharePoint Server 2013 server farm. You purchase an app for SharePoint from the Office Store. You plan to deploy the app to the farm. You need to recommend which changes must be made to the

Adding a host header in IIS configures how IIS responds to specific hostnames on the web server, but does not configure the DNS resolution needed for app domain URLs across the network.

Modifying the Hosts file on front-end web servers only affects name resolution on those specific servers, not the broader network DNS resolution required for app domain routing.

Modifying Web.config controls application-level settings for SharePoint web applications, but does not affect network-level DNS resolution required for app deployment.

SharePoint 2013 apps from the Office Store are hosted in a separate app domain to provide security isolation. This requires a wildcard DNS CNAME record pointing to the SharePoint farm so that app-specific subdomains can resolve correctly. Without this DNS entry, SharePoint cannot resolve the unique URLs generated for each deployed app.