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

The correct answer is:

D) To get a “YouTube” tab on the Google+ profile and for auto-sharing of uploads to Google+ with customized posts