Staged capacity managed retention in NetBackup storage lifecycles is indeed only available on disk storage units. This feature allows automatic movement of backups between different storage tiers based on retention policies. Option B is false because backups can be ejected early if space is needed. Option C is false because data classifications are not required for tape. Option D is false because backup types in storage lifecycle context refer to Full, Differential, and Incremental, not backup/duplicate/catalog.