Which describes the VNX Snapshot source LUN write process?

A.
Host issues write.
New data is written to a new location.

B.
Host issues write.
Old data is copied to the reserve LUN pool.
New data is written to the source LUN.

C.
Host issues write.
Data is written to the reserve LUN pool.

D.
Host issues write.
Old data is copied to the source LUN.
New data is written to the reserve LUN pool.