Which of the following is NOT a security feature relating to user accounts？（）

• A、Some commands can be password protected requiring logged in customers to re-enter their password.
• B、A user account can be disabled automatically， after a specified number of invalid login attempts.
• C、An account can have multiple valid passwords at the same time， any of which can be used to access the account.
• D、The password policy feature can allow the system to require passwords to include a minimum number of numeric characters.
• E、Logged in customers can be logged off of the system after a specified period of inactivity.