Which file extension is commonly associated with Microsoft Word documents?

The file extension that is commonly associated with Microsoft Word documents is .docx. This format was introduced with Microsoft Word 2007 as the default file format for saving documents. The .docx format is based on XML (Extensible Markup Language), which allows for more efficient storage and improved data recovery in comparison to the older .doc format.

Files saved in .docx can include a range of features such as text, images, tables, and graphs, making it a versatile choice for word processing tasks. This format is widely recognized and utilized not only in Microsoft Word but also across other applications that are compatible with Microsoft Office documents.

In contrast, the other file extensions represented in the choices serve different purposes. The .xlsx extension is used for Microsoft Excel spreadsheets, .pptx is associated with Microsoft PowerPoint presentations, and .txt denotes plain text files without any formatting. Understanding the specific use of each file extension is crucial for managing documents effectively in different applications.