The Business Partner technical specialist is called to check if the addition of host ports on an IBM System Storage DS8000 system has improved users’ response times for an IBM System p server running SAP.  How can the improvement be verified（）

A.check the output of the vmstat command on AIX

B.check the performance reports via TotalStorage Productivity Center for Data

C.check the performance reports via TotalStorage Productivity Center for Disk

D.check the improvement through the TotalStorage Expert report