Linking a YouTube channel to a Google+ page lets you:

A) manage one channel from one Google account and let multiple people manage a channel
B) manage one channel from one Google account
C) manage multiple channels from one Google account
D) manage multiple channels from one Google account and let multiple people manage a channel

The correct answer is:

D) manage multiple channels from one Google account and let multiple people manage a channel

Read more here: https://support.google.com/youtube/answer/4642409