单项选择题
A.It tells the router or switch to try establish an SSH connection first and if that fail to use telnet.
B.It configures a cisco network device to use the SSH protocol on incoming communications via the virtual terminal ports.
C.It allows seven failed login attempts before the VTY lines are temporarily shutdown.
D.It configures the virtual terminal lines with the password 030752180500.
E.It configures SSH globally for all logins.