What technology, used by Dell EMC Unity XT Snapshots, is accurately described?

What technology, used by Dell EMC Unity XT Snapshots, is accurately described?
A . Copy on First Write requires a storage resource reserved to hold original data that changed to preserve the point-in-time view
B . Redirect on Write requires a storage resource reserved to hold original data that changed to preserve the point-in-time view
C . Redirect on write requires no storage resource to create a Snapshot, writes are redirected on parent pool
D . Copy on First Write requires no storage resource to create a Snapshot, writes are copied to parent pool

View Answer

Answer: B

Explanation:

Reference: https://www.dellemc.com/bs-ba/collaterals/unauth/white-papers/products/storage/h15089­dell_emc_unity-snapshots_and_thin_clones.pdf (9)