Explanation:
BACKUP INCREMENTAL command helps you to make consistent or inconsistent incremental backups of the database or individual table spaces or data files. The CONFIGURE DEVICE TYPE … PARALLELISM command configures the device types that are eligible for use in jobs that use automatic channels and sets the degree of channel parallelism. The DISK device type is the default. The PARALLELISM parameter specifies the number of automatic channels of the specified device type allocated for RMAN jobs. RMAN always allocates the number of channels specified by PARALLELISM, although it may actually use only a subset of these channels. Incorrect Answer:
1: The NO CHECK SUM suppresses block checksums. Unless you specify this option, Oracle computes a checksum for each block. RMAN verifies the checksum when restoring the copy. If the database is already maintaining block checksums, then this flag has no effect.
2: The SET MAX CORRUPT FOR DATA FILE command sets a limit on the number of previously undetected physical block corruptions that Oracle will allow in a specified data file or list of data files.
3: If you specify the CHECK LOGICAL option, RMAN checks for logical and physical corruption.
Reference:
OCP Oracle 9i Database: Fundamentals II Exam Guide, Rama Velpuri, p. 224-225
Chapter 9: Oracle Recovery Manager Overview and Configuration

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