How do search engines use sitemaps?

Question: How do search engines use sitemaps?

• Google uses a sitemap to locate structured data on a web page and display it in rich results.
• Web crawlers use a sitemap to understand a website’s structure so they can evaluate and rank it more easily.
• Web crawlers use a sitemap to follow backlinks from one site to another and assign authority to those pages.
• Search engines don’t use sitemaps, but SEO experts use them to determine the information architecture of a website.

The right answer was: Web crawlers use a sitemap to understand a website’s structure so they can evaluate and rank it more easily.