A <span> block is an inline-level element.

A <span> element is indeed classified as an inline-level element in HTML. This means that it typically only takes up as much width as necessary to contain its content and does not break the flow of text around it. In practice, inline elements like <span> can be placed within block-level elements, such as <div>, and they will not start a new line.

Although it is possible to change the display property of <span> to block using CSS, which would make it behave as a block-level element, by default, it maintains its inline nature. Therefore, the statement about <span> being an inline-level element is accurate based on standard HTML definitions.

The other options provide various contexts that distract from the fundamental nature of the <span> element. While block-level and inline-level designation may vary in CSS, the inherent definition of a <span> as an inline element remains consistent across versions of HTML.