What can a Sitelink ad extension provide?

A call-to-action button in your text ad
An extra non-clickable snippet of text that highlights your website’s products or offers
A phone number that is not associated with a particular location, but is appropriate for all locations where your ads display
Additional links in your ads that take customers to specific pages on your website

The correct answer is:

Additional links in your ads that take customers to specific pages on your website.