Which two statements about IS-IS authentication are true? (Choose two)

Which two statements about IS-IS authentication are true? (Choose two)
A . if LSP authentication is in use, unauthorized devices can be form neighbor adjacencies
B . Area and domain authentication must be configured on a per-interface basis
C . Passwords can be configured on a per-interface basis
D . Level 1 LSPs use the domain password
E . Level 2 LSPs use the domain password encrypted inside the IS-IS PDU

Answer: C, E