Which command is used to swap the SRDF devices in the devices group “rdfgd”, and to mark any modified tracks on the original R1 device to refresh form data on the original R2 device, in a failover scenario?

A.
symrdf rdfdg swap refresh R2

B.
symrdf rdfdg swap refresh R1

C.
symrdf rdfdg swap -update R1

D.
symrdf rdfdg swap -update R2