Which two statements about the above index are true?

Examine the following output:
SQL> SELECT index_name,status
FROM dba_indexes
WHERE status=’UNUSABLE’;
INDEX_NAME STATUS
————————– —————
EIND UNUSABLE
Which two statements about the above index are true? (Choose two.)

A.
It is ignored by the query optimizer.

B.
It is not used while the index is being rebuilt.

C.
The index cannot be rebuilt, and has to be re-created.

D.
The index is automatically rebuilt when used the next time.