During which event will HPE 3par Storeserv persistent port feature provide transparent and uninterrupted failover (Select two)

During which event will HPE 3par Storeserv persistent port feature provide transparent and uninterrupted failover (Select two)
A . Loss of persistent cache
B . B-series SAN switch upgrades
C . Firmware upgrade
D . Node maintenance or failure
E . Loss of full-mesh cluster interconnect

Answer: C,D