upwork seo test answer | Which of the following correctly describes what are considered to be “Doorway pages”?

Which of the following correctly describes what are considered to be “Doorway pages”?
• Pages with a permanent redirect(301) to an external page with relevant content.
• Pages especially designed to link partner sites.
• Sets of poor-quality pages where each page is optimized for a specific keyword or phrase. (Answer)
• None of these.