Explanation:
First script backups the entire database (backup level 0). Second one backups all blocks changed since the previous backup (incremental backup, level 1).
Incorrect Answers:
1: First script backups the entire database only on Sunday.
3: On other days of the week these scripts back up all blocks changed since the previous backup in all files.
4: On Sunday they backup all table spaces, not only SYSTEM.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 632-637
Chapter 13: Overview of Backup and Recovery

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