CORRECT TEXT
Who ever creates the files/directories on /data group owner should be automatically should be the
same group owner of /data.

Answer:

Explanation:
1. chmod g+s /data
2. Verify using: ls -ld /data
Permission should be like:
drwxrws— 2 root sysadmin 4096 Mar 16 18:08 /data
If SGID bit is set on directory then who every users creates the files on directory group owner
automatically the owner of parent directory.
To set the SGID bit: chmod g+s directory
To Remove the SGID bit: chmod g-s directory