Which of the Following Statements Is True Regarding the Domain

Which of the following statements is true regarding the domain authentication mode md5 hello command in the IS-IS process?

A) This command enables IS-IS Hello PDUs to carry authentication information.
B) IS-IS SNP and LSP can be flooded normally only when the domain authentication mode and password of all routers in the same routing domain are MD5 and hello.
C) IS-IS authentication cannot be applied to IPv6 environments.
D) Routing domain authentication enables Level-1 and Level-2 SNPs and LSPs to carry authentication information.