Click the Exhibit（s） button to view the EMPLOYEES table.      The EMPLOYEE table contains thousands of rows. The EMP_CODE column is the primary key column. At the end of every month， you are required to perform search queries based on the BASIC_SAL+COMM column values. Which type of index will you create？（）      

• A、 B-tree Index
• B、 Bitmap Index
• C、 Function-based Index
• D、 Partitioned Index