To prevent a specific user from scheduling tasks with at, what should the administrator do?
A. Add the specific user to /etc/at.allow file.
B. Add the specific user to [deny] section in the /etc/atd.conf file.
C. Add the specific user to /etc/at.deny file.
D. Add the specific user to nojobs group.
E. Run the following: atd –deny [user].
