Which feature allows users to listen to music offline?

The feature that allows users to listen to music offline is related to downloading music from the Apple Music library. When subscribers to Apple Music download their favorite songs, albums, or playlists, they can access this content without needing an active internet connection. This is particularly convenient for users who may want to conserve data or listen while traveling in areas with limited connectivity.

On the other hand, iTunes Connect is primarily aimed at developers and artists to manage app and music content, not for direct user access to offline listening. Find My iPhone is a security feature that helps locate lost devices, while FaceTime audio is a service for making voice calls over the internet and does not relate to music listening capabilities. Hence, the ability to download music for offline access is specific to the Apple Music library download feature and is why this choice is the correct one.