A user, jsmith, needs access to database files located on a server. Which of the following will add jsmith to the "dba" group and preserve existing group memberships?

Two specific users need access to a directory owned by root where backups are located. Which of the following commands would BEST ensure the specified users can access the backup files?

A Linux administrator wants to load the KVM module into the kernel. Which of the following commands should the administrator use?

A Linux administrator opens a ticket to have an external hard drive mounted. As a security policy, external storage kernel modules are disabled.
Which of the following is the BEST command for adding the proper kernel module to enable external storage modules?

A systems administrator needs to allow the Linux server to receive HTTP connections from Internet hosts. By default, the port for HTTP connections is blocked. Which of the following rules should be added in the firewall to allow this type of connection?