Explanation:
The RMAN provides possibility to skip unused blocks, incremental block-level backup and detection of corrupted blocks during backup. Incorrect Answer:
1: Both user-managed and RMAN backups allow you to perform backup of open database.
3: Both types of backup can do partial database backup.
Reference:
OCP Oracle 9i Database: Fundamentals II Exam Guide, Rama Velpuri, p. 269-270
Chapter 11: RMAN Backups

---