Which of the following replication methods provides a disaster recovery system with minimal downtime to normal operations？（）

A. Tape library
B. NAS
C. Optical jukebox
D. SAN

A.Amount of Memory
B.Number of HBAs
C.Hard drive cache size
D.ECC ability in memory

A. Inadequate RAM
B. Slow processor
C. PCI bus
D. Excessive network traffic