(b) (i) Your company has just purchased 12 disks to configured into RAID storage system. The requirement of your company is that the storage system should still be able to operate even though 4 out of the 12 disks are down/corrupted. Apply the appropriate RAID Levels to fulfil the requirement of your company. (6 marks) (ii) Caching is one of the important techniques in data storage and management. Explain the common cache management and cache flushing techniques used in a storage system. (6 marks)