Final answer:
The correct statement among the given options is b. A given HTML document can have multiple CSS files linked to it.
Step-by-step explanation:
The correct statement among the given options is b. A given HTML document can have multiple CSS files linked to it. This allows web developers to organize and separate styles by function or module, which can be especially useful in managing large projects.
To address the other options: a. When a browser requests a web page, the CSS files are not sent automatically unless they are linked within the HTML through link tags or inline style tags. c. The CSS files and the HTML documents do not need to be in the same directory; they can be linked to each other as long as the correct paths are specified. d. A single CSS file can be linked to multiple HTML documents, making it a key tool for maintaining consistency across several web pages.
The truth is that a single HTML document can be associated with multiple CSS files, which allows web developers to manage styles in an organized manner. CSS files are linked within HTML and can be stored in different directories, and one CSS file can serve many HTML documents.