Which statement correctly describes hard links in a Unix-like file system?

• A. Hard links reference the same inode as the original file and cannot link directories or span filesystems.
• B. Hard links can reference directories and can cross filesystems.
• C. Hard links are separate small files that reference a path.
• D. Hard links automatically update when the original file permissions change.

Answer: (A)

Hard links are extra directory entries that point to the same inode as the original file. The inode holds the file’s metadata and the data blocks, so both names refer to the same underlying file data. Because they share the same inode, removing one name doesn’t delete the data until all hard links are removed, and permissions or changes to the file affect all links since there’s only one inode to reflect those attributes. Hard links cannot point to directories, and they cannot span different filesystems because inodes are local to a filesystem.

That’s why describing them as referencing the same inode and being confined to a single filesystem without linking directories best captures how hard links work.