The bank-records bucket requires indefinite immutable retention, so its ILM rule must comply with StorageGRID S3 Object Lock requirements. NetApp specifies that a compliant ILM rule must create at least two replicated copies or one erasure-coded copy, those copies must reside on Storage Nodes, at least one placement must begin at day 0 using Ingest time, and at least one placement must continue forever. Critically, copies governed by a compliant S3 Object Lock rule cannot be stored in a Cloud Storage Pool.

This requirement directly eliminates A, B, and C because every one of those choices introduces a Cloud Storage Pool. The organization's general preference to use cloud storage for long-term data does not override StorageGRID compliance restrictions for Object Lock-protected content.

NetApp's own bank-records example uses precisely this design: the bucket-specific compliant rule retains an erasure-coded copy on Storage Nodes from day 0 to forever.

Therefore, D is correct. Other noncompliant buckets can still use separate ILM rules that transition data to Cloud Storage Pools after six months, but immutable bank-records objects must remain on compliant StorageGRID Storage Node placements indefinitely.

Reference topics: ILM → S3 Object Lock → Compliant ILM Rules → Storage Nodes → Forever Retention → Cloud Storage Pool Restrictions