While explaining to a customer the fault tolerant benefits of x445 they ask what happens if they implement memory mirroring and a DIMM fails in the SMP expansion module.  Which of the following is the most appropriate response？（）

A.The DIMM is taken off line， and fault tolerance is available on the other DIMMs only.
B.The memory bank is taken offline and rebuilt with the online hot spare and then brought back on line.
C.The memory bank containing the failed DIMM is taken off line， and the system is no longer fault tolerant until replaced.
D.The DIMM is taken offline， and the online hot spare is initiated and the system remains fault tolerant.