For the p5 590 and p5 595 servers, the HMC must be directly attached. Why is the use of a private service network between HMC and the p5 590 required?（）

• A、The Bulk Power Controllers are dependent upon the HMC to provide them with DHCP  addresses.
• B、A firewall is required to isolate the private network from any of the open networks to which the HMC is attached.
• C、Network communications can be implemented through an open network. No private network  is required but it is recommended.
• D、All p5 590 and 595 servers are shipped with one service processor card. A private network is  required to manage DHCP addresses.