The administrator cannot log in to the Huawei router through Telnett, but other administrators can log in normally, so which of the following are the possible reasons? (Multiple Choice)
A . The authority level of the administrator user account has been modified to 0
B . The administrator user account has been disabled
C . The Te1net service of the AR2200 router has been disabled
D . The administrator user account has been deleted
Answer: BD