Which method is considered best practice?

A Linux print server must limit access to its printers. Only the database server must be allowed to print. Which method is considered best practice?

A.
Edit /etc/printcap and add a filter to only include the database server

B.
Limit file permissions on the printer filter to users on the database server

C.
Limit file permissions on the spool directory to users on the database server

D.
Edit /etc/hosts.lpd to only include the database server