View the Exhibit for some of the parameter settings. You start a session and issue the following command: SQL>CREATE INDEX emp_ename ON emp(ename) TABLESPACE users INVISIBLE; What is the outcome of the above command?（）

• A、The index is not used by the optimizer but is maintained during DML operations.
• B、The index is not used by the optimizer and is not maintained during DML operations.
• C、The index is used by the optimizer only if a hint is specified in the query statement and is maintained during DML operations.
• D、The index is used by the optimizer only if a hint is specified in the query statement but is not maintained during DML operations.