When you upload your Web site to a Web server, the file references can remain unchanged as long as:

When uploading a website to a web server, keeping the same file references is contingent upon maintaining the existing directory structure. This means that all paths to CSS files, JavaScript files, images, and other resources need to remain consistent with how they are referenced in the HTML or other code files. If you maintain this structure, the web server will be able to locate the files based on the provided references without any issues.

For example, if a web page references a CSS file using a path such as "/css/styles.css", it expects that there is a folder named "css" at the correct location relative to the root or intended point of access, containing the "styles.css" file. If the directory structure is altered, such as moving these files into different folders or changing their names, the references will break, resulting in missing styles or functionality on the website.

The other options do not directly influence the ability to keep file references unchanged. Supporting PHP, being in the root directory, or securing the site with HTTPS does not affect how file paths are structured or how files are located by the server. These aspects are important for other functionalities but are separate from the concern about maintaining file references through the directory structure.