Question: "What connection supports video playback on YouTube Red?"  Context: "YouTube Red is YouTube's premium subscription service. It offers advertising-free streaming, access to exclusive content, background and offline video playback on mobile devices, and access to the Google Play Music "All Access" service. YouTube Red was originally announced on November 12, 2014, as "Music Key", a subscription music streaming service, and was intended to integrate with and replace the existing Google Play Music "All Access" service. On October 28, 2015, the service was re-launched as YouTube Red, offering ad-free streaming of all videos, as well as access to exclusive original content."  Answer:
A:
offline