What is a feature of the WMV file format?

The feature of the WMV (Windows Media Video) file format is that it is primarily designed for video content and can indeed be used for media distribution, including formats compatible with DVDs and Blu-ray Discs. WMV files utilize different codecs to provide high-quality video compression and are often used for streaming over the internet and for playback on various devices, including computers.

While WMV files do support audio as part of the video structure, their main purpose is to encapsulate video streams, making them suitable for use in video-related applications, such as for DVDs and Blu-ray Discs. This versatility in playback and compatibility with different types of media makes WMV an important format for distributing video content.

The other options focus on features that don't accurately represent WMV's capabilities: it is not primarily for images, does not necessarily require proprietary software for playback since there are various players that support it, and it is not limited to only audio.