To solve this question, the user needs to understand the concept of indexes and how they work. An index is a data structure that improves the speed of data retrieval operations on a database table. It is created on one or more columns of a table to allow faster search and retrieval of data based on the values stored in those columns.

Now, let's go through each option and determine whether or not it will use the associated index on EMPNO:

A. select * from EMP where nvl(EMPNO, '00000') = '59384';

This option will not use the associated index on EMPNO. The nvl function in the where clause of this query will cause a full table scan to be performed instead of using the index. This is because the function modifies the column value, making it impossible to use the index for a direct lookup.

B. select * from EMP where EMPNO = '59384';

This option will use the associated index on EMPNO. The query filters on the exact value of EMPNO, which makes it possible to use the index for a direct lookup.

C. select EMPNO, LASTNAME from EMP where EMPNO = '59384';

This option will use the associated index on EMPNO. The query filters on the exact value of EMPNO and only selects the EMPNO and LASTNAME columns, making it possible to use the index for a direct lookup and avoid accessing the table rows.

D. select 1 from EMP where EMPNO = '59834';

This option will use the associated index on EMPNO. The query filters on the exact value of EMPNO, and although it does not retrieve any column values, the index can still be used to perform the lookup and avoid the full table scan.

Therefore, the option that will not use the associated index on EMPNO is:

A. select * from EMP where nvl(EMPNO, '00000') = '59384';

The Answer is: A