How Can a Specific User Be Prevented from Scheduling Tasks

Multiple Choice

How can a specific user be prevented from scheduling tasks with at ?

A) By adding the specific user to the /etc/at.allow file. By adding the specific user to the /etc/at.allow file.
B) By adding the specific user to the [deny] section in the /etc/atd.conf file. [deny] section in the /etc/atd.conf
C) By adding the specific user to the nojobs group. nojobs group.
D) By adding the specific user to the /etc/at.deny file. /etc/at.deny
E) By executing the atd --deny [user] command. By executing the atd --deny [user] command.