Which attribute is necessary for the <img> tag to display an image?

The src attribute is essential for the tag because it specifies the path to the image file that needs to be displayed. Without the src attribute, the browser has no information about where to find the image, and as a result, it cannot render anything for that tag. This makes the src attribute a fundamental part of using the tag effectively, as it's what links the HTML document to the actual image resource.

Other attributes related to the tag, such as alt, href, and title, serve different purposes. The alt attribute provides alternative text for the image, which is important for accessibility and SEO, but it does not influence the display of the image itself. The href attribute is used in tags for hyperlinks, and the title attribute provides additional information about the image when hovered over, but again, none of these would enable the image to be displayed on the page without the src attribute being present.