HTML and CSS Certification Practice Test

To display a list horizontally instead of vertically using CSS, applying the property `display: inline;` is appropriate because it changes the display behavior of the list items (typically `<li>` elements) from block-level to inline elements. By setting the list items to inline, they will line up next to each other, achieving a horizontal arrangement.

In a standard unordered or ordered list, each list item is block-level by default, which means they stack vertically. Changing this to inline allows each item to flow inline with the others, effectively displaying them side by side. This method is straightforward for achieving horizontal layouts without altering the markup.

The other options, although they may influence layout in various ways, do not directly achieve the desired outcome of displaying a list horizontally. For instance, using float can achieve a similar effect, yet it may require additional handling of layout and clearing floats. Utilizing list-style: none merely removes bullet points or numbering, and position: absolute would take elements out of the normal document flow, which might not suffice for a straightforward horizontal list layout.