Which logical entity must be configured before creating a Storage Pool?

Protection Domain (Option B): The Protection Domain (PD) is the parent container in the PowerFlex hierarchy.

Hierarchy: Protection Domain $\rightarrow$ Storage Pool $\rightarrow$ Device (Disk).

Logic: A Storage Pool cannot exist in a vacuum; it must belong to a specific Protection Domain. The PD defines which group of SDS nodes the pool spans. You must create the PD first, add SDSs to the PD, and then create the Storage Pool inside that PD.