A router has been configured with the settings shown below:[edit]user@host show system authentication-order authentication-order [ radius tacplus ];The router also has a local database that contains the user lab with password lab123. What would happen if both the RADIUS and the TACACS servers are not accessible?（）
A.The user lab will not be able to login.
B.The user lab will be authenticated against the local database and will be able to login.
C.The user lab will receive an error message indicating the router is unable to authenticate due to the authentication servers not responding.
D.The user will be able to login only if tries to login as the root user.
参考答案：B
