From an application perspective what should be done prior to performing an SRDF Fallback operation?

From an application perspective what should be done prior to performing an SRDF Fallback operation?
A . Continue accessing the R2 devices
Start accessing the R1 devices before running the command
B. Stop accessing the R2 devices
Run the command and then start accessing the R1 devices
C. Stop accessing the R2 devices
Start accessing the R1 devices before running the command
D. Continue accessing the R2 devices
Run the command and then start accessing the R1 devices

View Answer

Answer: B