How can you properly link to the about.html page from the index.html page?

The correct way to link to the about.html page from the index.html page is by using the anchor tag with the href attribute. The href attribute specifies the URL of the page the link goes to. This is why the solution using the anchor tag as shown is appropriate.

When a user clicks on "About This Site," they are directed to about.html, making it intuitively clear for navigation. The href attribute effectively establishes a hyperlink, directed toward the location of the other webpage.

The other options don't utilize the proper HTML practices for creating links. For instance, using "src" is applicable to elements like images or scripts but not to anchor tags, while the "link" tag is typically used for linking stylesheets and does not create visible hyperlinks in the document. Lastly, "rel" is not a valid attribute for defining links; it specifies the relationship of the linked document to the current document but does not change where the link points.