What is the reason for using mirrored cache in Dell EMC Unity storage systems?

A. Provide a secondary copy of write data for the same Storage Processor

B. Provide a secondary copy of read cached data for the peer Storage Processor

C. Provide the only copy of read data for each Storage Processor

D. Provide a secondary copy of write cached data for the peer Storage Processor

Reference: https://www.emc.com/collateral/white-papers/h15162-emc-unity-high-availability.pdf