Þ A. THE SUM AGGREGATE FUNCTION IGNORES NULL VALUES AND ADDS NON-NU...

3. þ A. The SUM aggregate function ignores null values and adds non-null PART IIvalues. Since nine rows contain the SALARY value 100, 900 is returned.ý B, C, and D. B would be returned if SUM(NVL(SALARY,100)) were executed. C is a tempting choice, since regular arithmetic with NULL values returns a NULL result. However, the aggregate functions, except for COUNT(*), ignore NULL values.