Refer to the Exhibit.

A company has three data centers and has decided to protect its data using SRDF. The replication design must ensure there will be no data loss if Site A fails. All data centers are within 200 km of each other. Either Site B or Site C should be able to take over as production sites in the event of the failure of Site A. SRDF/S is used between Sites A and B.
How should SRDF be configured between Sites B and C?

A.
Disk-based R21 devices with SRDF/A between Sites B and C

B.
Disk-based R21 devices with SRDF/S between Sites B and C

C.
Disk-less R21 devices with SRDF/A between Sites B and C

D.
Disk-less R21 devices with SRDF/S between Sites B and C