What are the basic configuration steps to enable IS - IS?（）

• A、Configure the net system - id command under routerisis and enable IS - IS on each interface with the ip router isis command.
• B、Configure the net sy stem - id and the network net - id commands under routerisis.
• C、Configure the network net - id command(s) under routerisis and enable IS - IS on each interface with the ip router isis command.
• D、Configure the network net - id command(s) and the is - type level -1- 2 command under routerisis.
• E、Configure the net system - id and the network net - id commands under routerisis and enable ISIS on each interface with the ip router isis command.