How are sitemaps important for the search engine optimization process?

Q) How are sitemaps important for the search engine optimization process?

Answers:
• Site maps help the search engine editorial staff to quickly go through a website, hence ensuring quicker placement
• Google gives credit to the websites having site maps. The GoogleBot looks for the keyword or title "Site Map" on the home page of a website.
• Site maps help the search engine spider pick up more pages from the website
• None of the above