For concurrent I/O, how do SmartCache and Endurant Cache differ?

For concurrent I/O, how do SmartCache and Endurant Cache differ?
A . Endurant Cache sends an acknowledgement to the client immediately after mirroring writes in NVRAM
B . Endurant Cache waits for acknowledgement from all nodes before copying to L2 cache
C . SmartCache immediately commits the write to NVRAM on the local node and one peer node
D . SmartCache uses sub-file, granular locking whereas Endurant Cache locks the entire file

View Answer

Answer: A