Why should a YouTube account be linked to a Google+ page?

Q) Why should a YouTube account be linked to a Google+ page?

  A)  So your video ads appear on Google+, too.
  B)  To get a “YouTube tab” on the Google+ profile.
  C)  For auto-sharing of uploads to Google+ with customized posts.
  D)  To get a “YouTube” tab on the Google+ profile and for auto-sharing of uploads to Google+ with customized posts.