Explanation:
A media management layer is always used when recover manager reads or writes to tapes.
Incorrect Answers:
2: A media management layer (MML) is not used to perform media recovery.
3: MML does not read or write to disk files.
4: It does not read or write trough a channel. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 611 Chapter 13: Using Recovery Manager for Backups

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