Which command changes the group ownership of a file or directory recursively?

• A. chmod g+srw <group>
• B. chgrp -R <group> <directory/ file>
• C. setfacl -R -m g:<group>:rwx <path>
• D. chown :<group> -R <path>

Answer: (B)

To change the group ownership of every file and directory inside a path, you want a command that is specifically about groups and can apply to a whole tree. The best fit is a dedicated group-change command with a recursive option. It directly updates the group field on each item, ensuring consistent group ownership across all files and subdirectories.

That command changes ownership metadata in a straightforward way and is purpose-built for this task. Using a permission-modifying tool (chmod) doesn’t affect who owns the item, so it won’t achieve the goal. ACL tools (setfacl) change access rules, not the ownership attributes themselves. While another command can change the group via a broader ownership-change syntax (such as chown with a colon to specify the group), the dedicated group-change utility is clearer and safer for this specific operation, especially when applied recursively with the appropriate flag.