How does an extension work on a Display ad?

• It adds extra information, like a location or phone number
• It extends the ad below the fold
• It adds a testimonial
• It extends the length of the ad placement

The correct Answer is:

• It adds extra information, like a location or phone number

Explanation: By adding extra pieces of information about the business to their ads, they’re giving customers more reasons to click.

Read more here: https://support.google.com/adwords/answer/2375499?hl=en