Hailey was working on a multimedia presentation that included both video and audio files. The file was huge, and she wanted to send it to her coworker in another office. She needed to reduce the size of the file so that it could be transmitted faster. The utility she used to do this was .

a compression software such as WinRar

Explanation:

The utility she used to do this would have been a compression software such as WinRar. This software compresses large files or various files into a single ZIP or RAR file. This compressed file is much smaller than the original files that it contains, which is accomplished through a compression algorithm. This can also be encrypted with a password so that only specific individuals with access can open the file. Once unzipped or extracted, the original files are obtained in its original size.