A. Rank high in search engines for a keyword phrase, B. Higher leads, and sales. C. Better user experience and D. Quality Score for Adwords are correct. Those who use Google often will be very familiar with landing pages.
When a person searches on Google, they may see ads at the top of the results. When they click one of those ads, they are taken to the associated site, which is the page they land on or the landing page. If a landing page is rich, it will make the visitor want to stay on the page and hopefully buy something on the site.