Explanation:
It can be used with data files and backup sets. The BACKUP ... DELETE INPUT command can delete archived redo logs, data file copies, and backup sets after backing them up. This functionality is especially useful when backing up archived logs on disk to tape. RMAN backs up one and only one copy of each log sequence number, and then deletes the file that it backs up. Incorrect Answer:
3: The RMAN BACKUP command using the DELETE INPUT option cannot be used with control files.
Reference:
OCP Oracle 9i Database: Fundamentals II Exam Guide, Rama Velpuri, p. 269-270
Chapter 11: RMAN Backups

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