What purpose does the symrdf update command serve?

A.
In an SRDF Fallback state, the update command will restore the R2 Volume back to the R1 Volumes.

B.
When in a Failover state, the update function will reset the /var/symapi/db/symapi_db.bin file.

C.
In an SRDF Failover state, update will begin synchronization prior to resuming operations on the source volumes.

D.
A symrdf update command will reinitialize all the SRDF device groups.