A customer has requested a proposal for a p5-520 with AIX 5.2 and Sysback.  There are no plans to run LPARs or Micro-Partitions on the p5-520 in the near future.  The customer has asked the pSeries technical specialist to recommend anything else that may be needed.  Which of the following should be recommended in this situation？（）

• A、HMC
• B、DVD-ROM
• C、Tape drive
• D、Network switch