Explanation:
Oracle9i simplifies the process of converting a LONG or LONG RAW column into a CLOB or BLOB column respectively. You use the ALTER TABLE … MODIFY statement to change a LONG or LONG RAW column into a CLOB or BLOB column respectively.
Incorrect Answers:
1: The ALTER TABLE … MODIFY statement can only convert a LONG or LONG RAW to a CLOB or BLOB column respectively. It will not change a VARCHAR or a RAW column into a LOB column.
4: The ALTER TABLE … MODIFY statement will not change a VARCHAR or a RAW column into a LOB column.
Reference:
OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 262-263
Chapter 5: Language Enhancements
Oracle 9i New Features, Robert Freeman, p. 147
Chapter 5: Miscellaneous Oracle9i Features and Enhancements

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