You have just configured the network interface on systemA . The following information is  From systemB， you test the network connectivity by sending ICMP ECHO_REQUEST packets to  systemA. The following message is displayed： no answer from systemA  What is most likely the problem？（）

• A、 The interface is not plumbed.
• B、 The interface is not configured.
• C、 The interface does not have valid routes configured.
• D、 The interface is not marked as