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