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

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