A、 All messages at the emerg priority level and below from all facilities and messages at the crit priority level and below from the mail and daemon facilities are sent to the TTY of the user sysadmin. 

B、 All messages at the emerg priority level and above from all facilities, all messages at any priority level from the mail facility, and all messages at the crit priority level and above from the daemon facilities are sent to the remote host sysadmin. 

C、 All messages at the emerg priority level and above from all facilities and messages at the crit priority level and above from the mail and daemon facilities are sent to the remote host sysadmin. 

D、 All messages at the emerg priority level and above from all facilities except for the mail facility and messages at the crit priority level and above from the daemon facility are sent to the TTY of the user sysadmin.