Final answer:
The file named vacation. is a graphics file due to its extension, which identifies it as a JPEG image.
Step-by-step explanation:
The file named vacation. is a graphics file. The extension indicates that it is a JPEG (Joint Photographic Experts Group) image, which is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. Therefore, the correct answer to the question is C. graphics file. Other file types mentioned, like Microsoft Word document, text file, and webpage have different extensions such as '.docx' for Word documents, '.txt' for text files, and '.html' or '.php' for webpages.