DCNM is capable of monitoring the network performance of a SAN. What are the three primary areas of this operation？ （）  

• A、 analyze traffic， device management， and network monitoring
• B、 DCNM-SAN， DCNM-LAN， and device manager
• C、 definition of flows， information collection， and data presentation
• D、 SNMP poll data， MIB analysis， and report generation