What is the purpose of the last command entered?

The following commands are entered on the router:
Burbank(config)# enable secret fortress
Burbank(config)# line con 0
Burbank(config-line)# login
Burbank(config-line)# password n0way1n

Burbank(config-line)# exit
Burbank(config)# service password-encryption
What is the purpose of the last command entered?

A.
to require the user to enter an encrypted password during the login process

B.
to prevent the vty, console, and enable passwords from being displayed in plain text in the
configuration files

C.
to encrypt the enable secret password

D.
to provide login encryption services between hosts attached to the router

Explanation:
Explanation/Reference:
Certain types of passwords, such as Line passwords, by default appear in clear text in the
configuration file. You can use the service password-encryption command to make them more
secure. Once this command is entered, each password configured is automatically encrypted and
thus rendered illegible inside the configuration file (much as the Enable/Enable Secret passwords
are). Securing Line passwords is doubly important in networks on which TFTP servers are used,
because TFTP backup entails routinely moving config files across networks—and config files, of
course, contain Line passwords.