Users complain SQL statements using a particular index fail. Using DBVERIFY， you find that two separate blocks in the index have become corrupt. The database data files for user data and index are very large.  What is the least disruptive recover strategy available in Oracle9i？（）

Rebuild the index using the online option.

Take the individual data file offline (not the whole tablespace), restore and recover the data file from backup with RMAN, then set the data file online again.

Without setting the individual data file offline, use RMAN with Block Media Recovery to restore and recover only those blocks.

Take the individual data file (not the whole tablespace) offline, use RMAN with Block Media Recovery to restore and recover only those blocks, then set the data file online again.