单选题What must an administrator do to prevent new telnet users from connecting to the system?（）A rmdev -l /dev/ptsB touch /etc/nologinC chdev -l sys0 -a nologinD chuser -a login=false ALL
题目
单选题
What must an administrator do to prevent new telnet users from connecting to the system?（）
A
rmdev -l /dev/pts
B
touch /etc/nologin
C
chdev -l sys0 -a nologin
D
chuser -a login=false ALL