The following query retrieves the LAST_NAME, SALARY, and COMMISSION_PCT values for employees whose LAST_NAME begins with the letter "R". Based on the following query, choose the ORDER BY clause that first sorts the results by the COMMISSION_PCT column, listing highest commission earners first, and then sorts the results in ascending order by the SALARY column. Any records with NULL COMMISSION_PCT must appear last: SELECT LAST_NAME, SALARY, COMMISSION_PCT
FROM EMPLOYEES
WHERE LAST_NAME LIKE 'R%'