Which utility would you use to change file permissions in Linux?

The utility used to change file permissions in Linux is chmod. This command allows users to define who can read, write, or execute a file through specific permission settings. Permissions can be set for the file owner, the group associated with the file, and others, using symbolic notation (such as 'r' for read, 'w' for write, and 'x' for execute) or numeric representation (using numbers to denote permissions, like 755). Understanding file permissions is crucial for maintaining security and managing access to files effectively in a Linux environment.

The other options serve different purposes: chown is used to change the ownership of a file or directory, lsmod lists the currently loaded kernel modules, and cp is a command for copying files and directories, making them irrelevant for the task of altering file permissions.