How do you define a list item in an unordered list?

To define a list item in an unordered list, the correct choice is the <li> tag. This tag stands for "list item" and is used specifically within both ordered lists (created with the <ol> tag) and unordered lists (created with the <ul> tag).

When you use the <li> tag within an unordered list, it denotes an individual item within that list. The structure looks like this:

<ul>

<li>Item 1</li>

<li>Item 2</li>

<li>Item 3</li>

</ul>

Each <li> represents a bullet point or marker for each item in the list, providing a clear and organized way to present related pieces of content in a format that users can easily read and understand. This semantic structure enhances both the clarity for users and the accessibility of the webpage.

The other provided options do not represent correct HTML syntax for defining list items. The tags <item>, <ulitem>, and <listitem> are not valid HTML tags for creating list items and would not display as intended in a browser, leading to confusion or errors in the webpage layout.