DPM uses Volume Shadow Copy Service (VSS) to create point-in-time snapshots for backup and recovery. VSS allows DPM to capture consistent data states even for active files. BITS is for background file transfers (not DPM's core backup mechanism). Indexing Service is for file content search (unrelated to DPM). 'All of the above' is incorrect because only VSS is the core technology DPM relies on for backup snapshots.