Which of the following is a common digital file format for images?

The choice of JPEG (Joint Photographic Experts Group) as a common digital file format for images is correct due to its widespread use and efficiency in compressing photographic images. JPEG is designed for storing and transmitting photographs and complex images with gradients and variations in color. Its compression algorithm reduces file size significantly while maintaining an acceptable level of image quality, making it ideal for both web usage and personal photography.

In contrast, the other options represent formats that are used for different types of data. TXT is a plain text format that contains unformatted text, making it unsuitable for images. MP3 is specifically designed for audio files and is optimized for compressing sound data, thus it does not apply to image formats. Similarly, AVI is a video file format, intended for storing video and audio data, rather than images. Each of these formats serves distinct purposes and audiences, highlighting the utility of JPEG in the realm of digital imagery.