Which compression tool is used for operating on multiple files?

The correct choice for a compression tool that operates on multiple files is zip. The zip command is specifically designed to compress multiple files and directories into a single compressed archive file, making it convenient for storage and transfer. It allows users to specify multiple files or entire directories to be included in the archive, which can then be easily shared or stored in a compressed format to save space.

Tar, while often used for archiving (and it can then be compressed using gzip or bzip2), primarily creates a single archive file from multiple files but does not compress them itself unless combined with other commands. Thus, while it can manage multiple files, it doesn't inherently focus on compression like zip does.

Cpio is another archiving tool, but it is less commonly used for compression purposes in the same way zip is. It is more about managing file collections for backup and restoration rather than compressing files for storage.

Rsync is not a compression tool. Instead, it is primarily used for synchronizing files and directories between locations, with optional compression during transfer, but it’s not used to create compressed archives.

This makes zip the most appropriate choice when it comes to compressing multiple files into an archive.