Examine the structure of the EMPLOYEES table: You need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task?（）

• A、CREATE INDEX NAME_IDX (first_name, last_name);
• B、CREATE INDEX NAME_IDX (first_name AND last_name);
• C、CREATE INDEX NAME_IDX   ON (first_name, last_name);
• D、CREATE INDEX NAME_IDX   ON employees (first_name AND last_name);
• E、CREATE INDEX NAME_IDX   ON employees(first_name, last_name);
• F、CREATE INDEX NAME_IDX   FOR employees(first_name, last_name);